DOCSLIB.ORG

10.3 Sulfonate and Inorganic Ester Derivatives of Alcohols 443

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
10.3 Sulfonate and Inorganic Ester Derivatives of Alcohols 443 10_BRCLoudon_pgs5-0.qxd 12/5/08 1:34 PM Page 443 10.3 SULFONATE AND INORGANIC ESTER DERIVATIVES OF ALCOHOLS 443 R2C| CR2 L "H carbocation Lewis acid–base association X_ Brønsted acid–base (halide ion) H2O reaction $ $ R2C CR2 RR L A "X "H C C H3O| (10.14b) alkyl halide + R $ $R alkene Notice that the principles you’ve studied in Chapter 9 for the substitutions and eliminations of alkyl halides are valid for other functional groups—in this case, alcohols. SULFONATE AND INORGANIC ESTER 10.3 DERIVATIVES OF ALCOHOLS When an alkyl halide is prepared from an alcohol and a hydrogen halide, protonation converts the OH group into a good leaving group. However, if the alcohol molecule contains a group thatL might be sensitive to strongly acidic conditions, or if milder or even nonacidic conditions must be used for other reasons, different ways of converting the OH group into a good leav- ing group are required. Methods for accomplishing this objectiveL are the subject of this section. A. Sulfonate Ester Derivatives of Alcohols Structures of Sulfonate Esters An important method of activating alcohols toward nu- cleophilic substitution and b-elimination reactions is to convert them into sulfonate esters. Sulfonate esters are derivatives of sulfonic acids, which are compounds of the form R SO3H. Some typical sulfonic acids are the following: L SO3H H3C SO3H H3C SO3H cL LcL L methanesulfonic acid benzenesulfonic acid p-toluenesulfonic acid (The p in the name of the last compound stands for para, which indicates the relative positions of the two groups on the benzene ring. This type of nomenclature is discussed in Chapter 16.) A sulfonate ester is a compound in which the acidic hydrogen of a sulfonic acid is replaced by an alkyl or aryl group. Thus, in ethyl benzenesulfonate, the acidic hydrogen of benzenesul- fonic acid is replaced by an ethyl group. O O S S SOH acidic hydrogen SOC2H5 cLLS L cLLS L O O benzenesulfonic acid ethyl benzenesulfonate (a sulfonate ester) 10_BRCLoudon_pgs5-0.qxd 12/5/08 1:34 PM Page 444 444 CHAPTER 10 • THE CHEMISTRY OF ALCOHOLS AND THIOLS Sulfur has more than the octet of electrons in these Lewis structures. Such “octet expansion” is com- mon for atoms in the third and higher periods of the periodic table. Bonding in sulfonic acids and their derivatives is discussed further in Sec. 10.9. Organic chemists often use abbreviated structures and names for certain sulfonate esters. Esters of methanesulfonic acid are called mesylates (abbreviated R OMs), and esters of p- toluenesulfonic acid are called tosylates (abbreviated R OTs). L L O S C2H5 OS CH3 is the same as C2H5 OMs L LSL L O ethyl mesylate ethyl methanesulfonate O S CH3CH2 CH OS CH3 is the same as CH3CH2 CH OTs L L LSLcL L L "CH3 O "CH3 sec-butyl p-toluenesulfonate sec-butyl tosylate PROBLEM 10.11 Draw both the complete structure and the abbreviated structure, and give another name for each of the following compounds. (a) isopropyl methanesulfonate (b) methyl p-toluenesulfonate (c) phenyl tosylate (d) cyclohexyl mesylate Preparation of Sulfonate Esters Sulfonate esters are prepared from alcohols and other sulfonic acid derivatives called sulfonyl chlorides. For example, p-toluenesulfonyl chloride, often known as tosyl chloride and abbreviated TsCl, is the sulfonyl chloride used to prepare tosylate esters. O S CH3(CH2)9OH Cl S CH3 + LSLcL + 1-decanol O N pyridine p-toluenesulfonyl (used as2 solvent) chloride (tosyl chloride; a sulfonyl chloride) O S (10.15) CH3(CH2)9O S CH3 Cl_ LLS cL + N| Further Exploration 10.1 O Mechanism of Sulfonate Ester decyl tosylate "H Formation (90% yield) This is a nucleophilic substitution reaction in which the oxygen of the alcohol displaces chloride ion from the tosyl chloride. The pyridine used as the solvent is a base. Besides catalyzing the re- action, it also neutralizes the HCl that would otherwise form in the reaction (color in Eq. 10.15). 10_BRCLoudon_pgs5-0.qxd 12/5/08 1:34 PM Page 445 10.3 SULFONATE AND INORGANIC ESTER DERIVATIVES OF ALCOHOLS 445 PROBLEM 10.12 Suggest a preparation for each of the following compounds from the appropriate alcohol. (a) cyclohexyl mesylate (b) isobutyl tosylate Reactivity of Sulfonate Esters Sulfonate esters, such as tosylates and mesylates, are useful because they have approximately the same reactivities as the corresponding alkyl bro- mides in substitution and elimination reactions. (In other words, you can think of a tosylate or mesylate ester group as a “fat” bromo group.) The reason for this similarity is that sulfonate anions, like bromide ions, are good leaving groups. Recall that, among the halides, the weak- est bases, bromide and iodide, are the best leaving groups (Sec. 9.4F). In general, good leav- ing groups are weak bases. Sulfonate anions are weak bases; they are the conjugate bases of sulfonic acids, which are strong acids. O O S S HO S CH3 _ O S CH3 or _ OTs 2 LLS cL 3 2 LLS cL 3 2 2 O 2 O 2 p-toluenesulfonic acid: p-toluenesulfonate anion a strong acid (tosylate anion): (pKa < 1) a weak base Thus, sulfonate esters prepared from primary and secondary alcohols, like primary and sec- ondary alkyl halides, undergo SN2 reactions in which a sulfonate ion serves as the leaving group. Nuc_ CH2 OTs Nuc CH2 _OTs (10.16) 3 L 21 L + 3 21 "R "R nucleophile tosylate leaving group Similarly, secondary and tertiary sulfonate esters, like the corresponding alkyl halides, also undergo E2 reactions with strong bases, and they undergo SN1–E1 solvolysis reactions in polar protic solvents. Occasionally we’ll need a sulfonate ester that is much more reactive than a tosylate or me- sylate. In such a case a trifluoromethanesulfonate ester is used. The trifluoromethanesulfonate group is nicknamed the triflate group and it is abbreviated OTf. L the triflate group, a very reactive leaving group O O R OS CF3 R OTf OS CF3 L L L L LL O abbreviation for O a triflate ester a triflate ester triflate anion a very weak base The triflate anion is a particularly weak base. (See Problem 10.46 on p. 478.) Hence, the tri- flate group is a particularly good leaving group, and triflate esters are highly reactive. For ex- ample, consider again the SN2 reaction used to prepare FDG, an imaging agent used in 10_BRCLoudon_pgs5-0.qxd 12/5/08 1:34 PM Page 446 446 CHAPTER 10 • THE CHEMISTRY OF ALCOHOLS AND THIOLS positron emission tomography (PET). (See Eq. 9.30a on p. 397.) This reaction is far too slow to be useful with a tosylate leaving group. However, the triflate leaving group has considerably greater reactivity and is an ideal leaving group for this reaction, which must be carried out quickly. Triflate esters are prepared in the same manner as tosylate esters (Eq. 10.15), except that triflic anhydride is used instead of tosyl chloride. O O CH3(CH2)4OH F3C S O S CF3 + + CH2Cl2 1-pentanol O O N triflic anhydride pyridine2 O CH3(CH2)4OTf O S CF3 + N| 1-pentyl triflate O (90% yield) "H (10.17) The use of sulfonate esters in SN2 reactions is illustrated in Study Problem 10.1. Study Problem 10.1 Outline a sequence of reactions for the conversion of 3-pentanol into 3-bromopentane. Solution Before doing anything else, write the problem in terms of structures. OH Br ? CH3CH2"CHCH2CH3 CH3CH2"CHCH2CH3 Alcohols can be converted into alkyl bromides using HBr and heat (Sec. 10.2). However, because secondary alcohols are prone to carbocation rearrangements, the HBr method is likely to give by-products. However, if conditions can be chosen so that the reaction will occur by the SN2 mechanism, carbocation rearrangements will not be an issue. To accomplish this objective, first convert the alcohol into a tosylate or mesylate. OH OTs TsCl CH CH "CHCH CH CH CH "CHCH CH (10.18a) 3 2 2 3 pyridine 3 2 2 3 Next, displace the tosylate group with bromide ion in a polar aprotic solvent such as DMSO (Table 8.2, p. 341). OTs Br CH CH "CHCH CH Na Br CH CH "CHCH CH Na OTs (10.18b) 3 2 2 3 | _ DMSO 3 2 2 3 | _ + + Because secondary alkyl tosylates, like secondary alkyl halides, are not as reactive as primary ones in the SN2 reaction, use of a polar aprotic solvent ensures a reasonable rate of reaction (Sec. 9.4E). This type of solvent also suppresses carbocation formation, which would be more likely to occur in a protic solvent. (The transformation in Eq. 10.18b takes place in 85% yield.) 10_BRCLoudon_pgs5-0.qxd 12/5/08 1:34 PM Page 447 10.3 SULFONATE AND INORGANIC ESTER DERIVATIVES OF ALCOHOLS 447 The E2 reactions of sulfonate esters, like the analogous reactions of alkyl halides, can be used to prepare alkenes: OTs M 20–25 C, 30 min M K (CH ) CO ° K OTs (CH ) COH | 3 3 _ DMSO | _ 3 3 (10.19) ` + y ++ H (83% yield) This reaction is especially useful when the acidic conditions of alcohol dehydration lead to rearrangements or other side reactions, or for primary alcohols in which dehydration is not an option. To summarize: An alcohol can be made to undergo substitution and elimination reactions typical of the corresponding alkyl halides by converting it into a good leaving group such as a sulfonate ester. PROBLEMS 10.13 Design a preparation of each of the following compounds from an alcohol using sulfonate ester methodology. (a) (b) I CH2CH2CH2 SCH3 LL 10.14 Give the product that results from each of the following sequences of reactions.
Load more

Recommended publications
  • Common Names for Selected Aromatic Groups
    More Nomenclature: Common Names for Selected Aromatic Groups Phenyl group = or Ph = C6H5 = Aryl = Ar = aromatic group. It is a broad term, and includes any aromatic rings. Benzyl = Bn = It has a -CH2- (methylene) group attached to the benzene ring. This group can be used to name particular compounds, such as the one shown below. This compound has chlorine attached to a benzyl group, therefore it is called benzyl chloride. Benzoyl = Bz = . This is different from benzyl group (there is an extra “o” in the name). It has a carbonyl attached to the benzene ring instead of a methylene group. For example, is named benzoyl chloride. Therefore, it is sometimes helpful to recognize a common structure in order to name a compound. Example: Nomenclature: 3-phenylpentane Example: This is Amaize. It is used to enhance the yield of corn production. The systematic name for this compound is 2,4-dinitro-6-(1-methylpropyl)phenol. Polynuclear Aromatic Compounds Aromatic rings can fuse together to form polynuclear aromatic compounds. Example: It is two benzene rings fused together, and it is aromatic. The electrons are delocalized in both rings (think about all of its resonance form). Example: This compound is also aromatic, including the ring in the middle. All carbons are sp2 hybridized and the electron density is shared across all 5 rings. Example: DDT is an insecticide and helped to wipe out malaria in many parts of the world. Consequently, the person who discovered it (Muller) won the Nobel Prize in 1942. The systematic name for this compound is 1,1,1-trichloro-2,2-bis-(4-chlorophenyl)ethane.
    [Show full text]
  • Optimizing the Least Nucleophilic Anion. a New, Strong Methyl+ Reagent Daniel Stasko and Christopher A
    Published on Web 01/25/2002 Optimizing the Least Nucleophilic Anion. A New, Strong Methyl+ Reagent Daniel Stasko and Christopher A. Reed* Department of Chemistry, UniVersity of California, RiVerside, California 92521-0304 Received August 3, 2001 The ideal weakly coordinating counterion for reactive cations would be the least nucleophilic, least basic, most inert anion available. It should also be inexpensive, have useful spectroscopic handles, and confer good solubility and crystallizing properties on - its salts. Triflate anion, CF3SO3 , has served chemistry well in this regard but larger size, absence of lone pairs, and extreme chemical inertness have recently made carboranes1 or fluorinated tetraphe- nylborates the preferred choice for many applications.2 These anions have led to the solution of the silylium ion problem,3 enhanced Lewis acid catalysis by Li+ ion,4-6 new “strong-but-gentle” superacids,7 commercially viable olefin polymerization catalysts,8 new possibilities for electrolytes9,10 and ionic liquids,11 and the •+ 7 + 12 isolation of new reactive cations such as C60 , Bu3Sn , Cu- + 13 (CO)4 , etc. Figure 1. The 1-H-2,3,4,5,6-pentamethyl-7,8,9,10,11,12-hexahalo-CB11 - ) The perfluorinated tetraphenylborate anion is the preferred choice carborane anions, 1-H-CB11Me5X6 (X Cl, Br, I), used in this work. for price and solubility reasons but its salts frequently form liquid 29 Table 1. Selected Si Chemical Shifts (ppm) for i-Pr3SiY clathrates and fail to crystallize. The boron-phenyl bond is rather 29 easily cleaved by strong Brønsted14 or Lewis15 acids. Halogenated compd Si conditions carborane anions are much more inert than tetraphenylborates, their i-Pr3Si(1-H-CB11H5Br6) 100 C6D6 salts crystallize well, but they are more expensive and their salts i-Pr3Si(1-H-CB11H5Cl6) 103 C6D6 i-Pr Si(F -BPh )a 108 solid state less soluble.
    [Show full text]
  • United States Patent Office
    Patented Mar. 30, 1948 2,438,754 UNITED STATES PATENT OFFICE 2,438,754 COPPER, CONTAINING DSAZO, DYESTUFFS Adolf Krebser, Riehen, near Basel, and Werner Bossard, Basel, Switzerland, assignors to the firm J. R. Geigy A. G., Basel, Switzerland No Drawing. Application March 1, 1943, Serial : No. 477,630. In Switzerland April 28, 1942 1. Claims. (C. 260-148) 2 - It has been found that valuable new Copper For the dyestuffs of the type (a): 2-amino containing disazo dyestuffs are obtained by 1-hydroxy-, -methoxy- or -benzyloxybenzene coupling a diazotised amino Sulfonic acid of the 4-Sulfonic acid, 4- or 6-methyl-2-amino-1-hy benzene or naphthalene series, which contains, in droxy- or ethoxybenzene sulfonic acid, 4- or o-position to the amino group, a hydroxy group 5 6-chloro-2-amino-1-hydroxy- or -methoxyben or a Substituent convertible into a hydroxy group Zene Sulfonic acid, 4- or 6-nitro-2-amino-1-hy. by coppering, with a 1:3-dihydroxy-benzene, droxy- or -methoxybenzene sulfonic acid, then causing a diazonium compound which is 1-amino-2-hydroxynaphthalene-4-sulfonic acid, free from sulfonic acid groups to react with the 6-nitro-2-amino-1-hydroxynaphthalene - 4 -sul said monoazo dyestuff and after-treating the 0. fonic acid. so-obtained disazo dyestuff with copper-yielding For the dyestuffs of the type (b) and (c) : agents, with the condition that at least one of 3-amino-4-hydroxy-, -methoxy- or -chloro-1:1'- the diazo components is substituted by a phenyl diphenylsulfone-5- or -3'-sulfonic acid, 3-amino nucleus bound by a non-basic bridge.
    [Show full text]
  • Cofactor Binding Protects Flavodoxin Against Oxidative Stress
    Cofactor Binding Protects Flavodoxin against Oxidative Stress Simon Lindhoud1., Willy A. M. van den Berg1., Robert H. H. van den Heuvel2¤, Albert J. R. Heck2, Carlo P. M. van Mierlo1, Willem J. H. van Berkel1* 1 Laboratory of Biochemistry, Wageningen University, Wageningen, The Netherlands, 2 Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands Abstract In organisms, various protective mechanisms against oxidative damaging of proteins exist. Here, we show that cofactor binding is among these mechanisms, because flavin mononucleotide (FMN) protects Azotobacter vinelandii flavodoxin against hydrogen peroxide-induced oxidation. We identify an oxidation sensitive cysteine residue in a functionally important loop close to the cofactor, i.e., Cys69. Oxidative stress causes dimerization of apoflavodoxin (i.e., flavodoxin without cofactor), and leads to consecutive formation of sulfinate and sulfonate states of Cys69. Use of 7-chloro-4- nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) reveals that Cys69 modification to a sulfenic acid is a transient intermediate during oxidation. Dithiothreitol converts sulfenic acid and disulfide into thiols, whereas the sulfinate and sulfonate forms of Cys69 are irreversible with respect to this reagent. A variable fraction of Cys69 in freshly isolated flavodoxin is in the sulfenic acid state, but neither oxidation to sulfinic and sulfonic acid nor formation of intermolecular disulfides is observed under oxidising conditions. Furthermore, flavodoxin does not react appreciably with NBD-Cl. Besides its primary role as redox- active moiety, binding of flavin leads to considerably improved stability against protein unfolding and to strong protection against irreversible oxidation and other covalent thiol modifications.
    [Show full text]
  • Secondary Alkane Sulfonate (SAS) (CAS 68037-49-0)
    Human & Environmental Risk Assessment on ingredients of household cleaning products - Version 1 – April 2005 Secondary Alkane Sulfonate (SAS) (CAS 68037-49-0) All rights reserved. No part of this publication may be used, reproduced, copied, stored or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise without the prior written permission of the HERA Substance Team or the involved company. The content of this document has been prepared and reviewed by experts on behalf of HERA with all possible care and from the available scientific information. It is provided for information only. Much of the original underlying data which has helped to develop the risk assessment is in the ownership of individual companies. HERA cannot accept any responsibility or liability and does not provide a warranty for any use or interpretation of the material contained in this publication. 1. Executive Summary General Secondary Alkane Sulfonate (SAS) is an anionic surfactant, also called paraffine sulfonate. It was synthesized for the first time in 1940 and has been used as surfactant since the 1960ies. SAS is one of the major anionic surfactants used in the market of dishwashing, laundry and cleaning products. The European consumption of SAS in detergent application covered by HERA was about 66.000 tons/year in 2001. Environment This Environmental Risk Assessment of SAS is based on the methodology of the EU Technical Guidance Document for Risk Assessment of Chemicals (TGD Exposure Scenario) and the HERA Exposure Scenario. SAS is removed readily in sewage treatment plants (STP) mostly by biodegradation (ca. 83%) and by sorption to sewage sludge (ca.
    [Show full text]
  • Chemistry 0310 - Organic Chemistry 1 Chapter 6
    Dr. Peter Wipf Chemistry 0310 - Organic Chemistry 1 Chapter 6. SN2 Reactions Nucleophilic substitution reactions occur when nucleophiles (electron-rich species) displace leaving groups on electrophiles (electron-poor species). The net result is the substitution of one group for another bonded to a carbon atom. Nucleophilicity is increased by a negative charge and an increase in the polarizability. The greater the size and the lower the electronegativity of an atom, the greater its polarizability. Leaving groups are stable species that can be detached with their bonding electrons from a molecule during reaction. Most good leaving groups are the conjugate bases of strong acids. Sulfonates (mesylates, tosylates, triflates, etc.) are popular leaving groups since they can be readily obtained from alcohols. Solvents also influence nucleophilicity. SN2 reactions are second-order reactions whose rates depend o the concentration of both the alkyl halide and the nucleophile. The transition state of the one-step SN2 process involves a trigonal bipyramidal carbon and results in an overall inversion of configuration. The order of reactivity of alkyl halides and alkyl sulfonates in SN2 reactions is CH3>1°>2°>3°. The activation energy, DG‡, determines the rate of a reaction: k = koexp(-DG‡/RT). The overall change in free energy, DG, determines the position of the thermodynamic equilibrium. A positive sign of DG is characteristic for an endergonic reaction, a negative DG is found for an exergonic process. The rate of a reaction can be measured and provides information about its mechanism. The reaction order is the sum of the exponents in the rate equation. Relative Leaving Group Abilities: Leaving Group Common Name krel AcO acetate 1 x 10-10 Cl chloride 0.0001 Br bromide 0.001 I iodide 0.01 O mesylate 1.00 H3C S O O O tosylate 0.70 H3C S O O O brosylate 2.62 Br S O O O nosylate 13 O2N S O O O fluorosulfate 29,000 F S O O O triflate 56,000 CF3 S O O O nonaflate 120,000 C4F9 S O O.
    [Show full text]
  • Leaving Group of Substrate Important
    1 Recap... • Last two lectures we looked at substitution reactions • We found that there we two (extreme) mechanisms • SN1 H H H H H PhS R H R Br R SPh Br • And SN2 H H H H PhS + Br R Br PhS R • We looked at many of the factors that influenced which ..mechanism was operating... • Now we will turn our attention to elimination reactions 2 Elimination reactions NaOH NaOH or low Br H2O OH concentration • You have seen SN1 substitution • Reaction not sped up by altering nucleophile - it is not in RDS • In fact if we increase the amount / concentration of nucleophile we get the following... high O H + + + Br Br OH concentration H H • We observe an elimination reaction • Overall HBr is lost from the molecule • Isn't chemistry fun - these are the same conditions as substitution! • Next two lectures will look at the mechanisms for elimination • And how we control the nature of the reaction we observe... 3 Elimination, bimolecular E2 O H Br HO Br H H • E2 - Elimination bimolecular or 2nd order reaction • 2 molecules in the RDS or transition state H H H H H C H C H H C Br Br H O H C H O H C C H H H H C H C H H H • Two molecules in the rate determining step • So both the base and the substrate control the reaction • Both carbon skeleton & leaving group of substrate important In substitutions nucleophile acts as a nucleophile & attacks carbon In eliminations nucleophile acts as a base & attacks proton 4 Elimination, bimolecular E2: MO • Little confusing as need bonding & anti-bonding in same diagram! • Orbitals need to be parallel for maximum overlap
    [Show full text]
  • Carbonyl Chemistry I: Additions to Carbonyl Groups
    Paul Bracher Chem 30 – Section 4 Carbonyl Chemistry I: Additions to Carbonyl Groups Section Agenda 1) Lessons from Exam I, Course Feedbeck Mechanism on Web Site 2) Carbonyl Groups: Structure, Bonding, Molecular Orbitals, Geometry, Reactivity 3) Handout: In-Section Problem Set 4) Handout: In-Section Solution Set 5) Weekly Office Hours: Thursday, 3-4PM and 8-9PM, in Bauer Lobby Structure and Bonding · Carbonyl carbons are roughly sp2 hybridized Molecular Orbital Picture and planar with bond angles near 120 degrees bonding p orbital antibonding p* orbital · The C=O p bond is formed by the overlap of two unhybridized p orbitals. The bond is polarized due to the different electronegativities of carbon and oxygen. 105 o Resonance Model O O Bürgi-Dunitz angle · Another way to picture carbonyl groups is I II through an MO picture. Since the coefficient of · Resonance form II suggests that the carbon pO’s contribution is greater in pC=O, then atom is surrounded by less negative charge conservation of blending atomic orbitals into density than oxygen, rendering the carbon more molecular orbitals tells you that pC must be a electrophilic. larger contributor to the p*C=O orbital. · When reagents add to carbonyl double bonds, · The larger coefficient on oxygen in the filled the nucleophile attacks the carbon atom. orbital explains why the oxygen atom behaves as a Lewis base (it commonly complexes with · Due to the increased negative charge density Lewis acids). The larger coefficient on carbon on oxygen, Lewis acids (such as protons) in the empty antibonding orbital explains why it commonly complex with oxygen.
    [Show full text]
  • Hydroxylamine-O -Sulfonic Acid — a Versatile Synthetic Reagent
    Hydroxylamine-O -sulfonic acid — a versatile synthetic reagent Raymond G. Wallacef School of Chemistry Brunei University Uxbridge, Middlesex UBS 3PH Great Britain imidazoli nones and related derivatives are time to these various modes of reaction. discussed in the review. Many of these The uses of HOSA as a reagent are organiz­ preparations can be carried out in high ed below according to the different syn­ yield, thetic transformations that it can bring about. Hydroxylamine-Osulfonic acid, NHj-OSOjH (abbreviated to HOSA in Probably by far the most well known this article) has become in recent years and explored reactions of HOSA are commercially available. Although much animation reactions, illustrating elec­ fruitful chemistry has been carried out us­ trophilic attack by HOSA, with amination ing HOSA, to this author's knowledge, on nitrogen being the most important, there has been no systematic review in although a significant number of English* of its use as a synthetic reagent. It animations on both carbon and sulfur have is a chemically interesting compound been reported, Amination on phosphorus because of the ability of the nitrogen center also occurs. to act in the role of both nucleophile and AMINATION electrophile, dependent on circumstances, Synopsis (a) At a nitrogen atom and thus it has proved to be a reagent of Hydroxylamine-0-sulfonic acid (0 Preparation of mono- and di- great synthetic versatility. (HOSA) has only recently become widely substituted hydrazines and trisubstituied commercially available despite the fact that H,N-Nu hydrazinium salts it has proved to be a valuable synthetic reagent in preparative organic chemistry.
    [Show full text]
  • Of Operation and Control Ion-Exchange Processes For
    TECHNICAL REPORTS SERIES No. 78 Operation and Control Of Ion-Exchange Processes for Treatment of Radioactive Wastes INTERNATIONAL ATOMIC ENERGY AGENCY,VIENNA, 1967 OPERATION AND CONTROL OF ION-EXCHANGE PROCESSES FOR TREATMENT OF RADIOACTIVE WASTES The following States are Members of the International Atomic Energy Agency: AFGHANISTAN GERMANY, FEDERAL NIGERIA ALBANIA REPUBLIC OF NORWAY ALGERIA GHANA PAKISTAN ARGENTINA GREECE PANAMA AUSTRALIA GUATEMALA PARAGUAY AUSTRIA HAITI PERU BELGIUM HOLY SEE PHILIPPINES BOLIVIA HUNGARY POLAND BRAZIL ICELAND PORTUGAL BULGARIA INDIA ROMANIA BURMA INDONESIA SAUDI ARABIA BYELORUSSIAN SOVIET IRAN SENEGAL SOCIALIST REPUBLIC IRAQ SIERRA LEONE CAMBODIA ISRAEL SINGAPORE CAMEROON ITALY SOUTH AFRICA CANADA IVORY COAST SPAIN CEYLON JAMAICA SUDAN CHILE JAPAN SWEDEN CHINA JORDAN SWITZERLAND COLOMBIA KENYA SYRIAN ARAB REPUBLIC CONGO, DEMOCRATIC KOREA, REPUBLIC OF THAILAND REPUBLIC OF KUWAIT TUNISIA COSTA RICA LEBANON TURKEY CUBA LIBERIA UKRAINIAN SOVIET SOCIALIST CYPRUS LIBYA REPUBLIC CZECHOSLOVAK SOCIALIST LUXEMBOURG UNION OF SOVIET SOCIALIST REPUBLIC MADAGASCAR REPUBLICS DENMARK MALI UNITED ARAB REPUBLIC DOMINICAN REPUBLIC MEXICO UNITED KINGDOM OF GREAT ECUADOR MONACO BRITAIN AND NORTHERN IRELAND EL SALVADOR MOROCCO UNITED STATES OF AMERICA ETHIOPIA NETHERLANDS URUGUAY FINLAND NEW ZEALAND VENEZUELA FRANCE NICARAGUA VIET-NAM GABON YUGOSLAVIA The Agency's Statute was approved on 26 October 1956 by the Conference on the Statute of the IAEA held at United Nations Headquarters, New York; it entered into force on 29 July 1957, The Headquarters of the Agency are situated in Vienna. Its principal objective is "to accelerate and enlarge the contribution of atomic energy to peace, health and prosperity throughout the world". © IAEA, 1967 Permission to reproduce or translate the information contained in this publication may be obtained by writing to the International Atomic Energy Agency, Kamtner Ring 11, A-1010 Vienna I, Austria.
    [Show full text]
  • Organic Chemistry Nomenclature Guide
    Chemistry 222 Organic Chemistry Nomenclature Guide Many molecules in organic chemistry can be named using alkyl groups. MEMORIZE THEM! Common Alkyl (R) Groups Number of Carbons Formula Name 1 -CH3 methyl 2 -CH2CH3 ethyl 3 -CH2CH2CH3 propyl 4 -CH2CH2CH2CH3 butyl 5 -CH2CH2CH2CH2CH3 pentyl 6 -CH2(CH2)4CH3 hexyl 7 -CH2(CH2)5CH3 heptyl 8 -CH2(CH2)6CH3 octyl 9 -CH2(CH2)7CH3 nonyl Alkyl groups are generically referred to as R-groups, where R could be a methyl group, ethyl group, octyl group, etc. Organic compounds are often lumped into families or classes of compounds. The classes we will study this term include the following: R H R O H R O R R X Alcohols Ethers Alkanes Cycloalkanes Alkyl Halides or haloalkanes O O C C C C R C R C R H Ketones Aldehydes Alkynes Alkenes Aromatics H O O O All of these families are detailed in the R N R C R C R C pages that follow. H O H O R NH2 Amides Amines Carboxylic Acids Esters Page IV-20-1 / Organic Chemistry Nomenclature Guide Alkanes Elemental Formula: CnH2n+2 H Nomenclature Guidelines: -yl on alkyl group, +ane to ending Notes: An alkane is an alkyl group plus a hydrogen, often referenced as R-H. H C H Alkanes contain only carbon and hydrogen atoms in long chains with no rings. Each 3 H carbon atom is sp hybridized. Alkanes make great fuels but are generally unreactive. methane, CH4 Example: CH4 - methane - is a methyl group plus a hydrogen (CH3-H) Example: C2H6 - ethane - is a ethyl group plus a hydrogen (CH3CH2-H) Cycloalkanes H Elemental Formula: CnH2n H Nomenclature Guidelines: cyclo+ -yl on alkyl group, +ane to ending C H Notes: Cycloalkanes are alkanes which form an internal ring within the H C C molecule.
    [Show full text]
  • Aldol Reactions: E-Enolates and Anti-Selectivity
    Utah State University DigitalCommons@USU All Graduate Plan B and other Reports Graduate Studies 5-2005 Aldol Reactions: E-Enolates and Anti-Selectivity Matthew Grant Anderson Utah State University Follow this and additional works at: https://digitalcommons.usu.edu/gradreports Part of the Organic Chemistry Commons Recommended Citation Anderson, Matthew Grant, "Aldol Reactions: E-Enolates and Anti-Selectivity" (2005). All Graduate Plan B and other Reports. 1312. https://digitalcommons.usu.edu/gradreports/1312 This Report is brought to you for free and open access by the Graduate Studies at DigitalCommons@USU. It has been accepted for inclusion in All Graduate Plan B and other Reports by an authorized administrator of DigitalCommons@USU. For more information, please contact [email protected]. ALDOL REACTIONS: E-ENOLATES AND ANTI-SELECTIVITY Prepared By: MATTHEW GRANT ANDERSON A non-thesis paper submitted in partial fulfillment of the requirement for a Plan B Degree of Masters of Science in Organic Chemistry UTAH STATE UNIVERSITY Logan, Utah 2005 Contents Page CONTENTS ...................................................................................... .i LIST OF TABLES, FIGURES AND SCHEMES ....................................... ii,iii ABSTRACT .................................................................................... iv CHAPTER I. ALDOL REACTIONS:E-ENOLATES AND ANTI SELECTIVITY ......... 1 CHAPTER II. SECTION 1. MODELS OF E-ENOLATE FORMATION ...... .... ....... ... 12 SECTION 2. PATERSON ENOLATE PAPER ..... .........................
    [Show full text]