Appendix I: Named Reactions

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problem set Single-bond forming reactions Grignard reaction various Radical couplings hirstutene Conjugate addition / Michael reaction strychnine Stork enamine additions Aldol-type reactions (incl. Mukaiyama aldol) various (aldol / Claisen / Knoevenagel / Mannich / Henry etc.) Asymmetric aldol reactions: Evans / Carreira etc. saframycin A Organocatalytic asymmetric aldol saframycin A Pseudoephedrine glycinamide alkylation saframycin A Allylations and crotylations zincophorin Prins reaction Stetter reaction problem set # 2 Benzoin condensation

Double-bond forming reactions prostaglandin Horner-Wadsworth-Emmons reaction prostaglandin Still-Gennari olefination general discussion and heteroaryl variants within the Corey-Winter olefination prostaglandin synthesis Barton extrusion reaction Tebbe olefination / other methylene-forming reactions tetrodotoxin hirstutene / Selenoxide elimination tetrodotoxin

Electrocyclic reactions and related transformations Diels-Alder reaction problem set # 1 Asymmetric Diels-Alder reaction prostaglandin problem set # 2 [2,3] sigmatropic rearrangement various 1,3-dipolar cycloadditions various and related periplanone Claisen rearrangement hirstutene

Oxidations – Also See Handout # 1 Swern-type oxidations (Swern / Moffatt / Parikh-Doering etc. N1999A2 Jones oxidation progesterone TPAP / NMO oxidation tetrodotoxin PCC oxidation dragmacidin Dess-Martin oxidation Allylic oxidations tetrodotoxin General epoxidation reactions periplanone Asymmetric epoxidations: Sharpless / Jacobsen / Shi etc. N1999A2 Sharpless asymmetric dihydroxylation Ozonolysis tetrodotoxin / Lemieux-Von Rudloff oxidation progesterone Baeyer-Villiger oxidation prostaglandin Rubottom oxidation periplanone Phenol oxidation (quinone formation) saframycin A Tamao-Fleming oxidation sparteine

Reductions - Also See Handout # 3 CBS reduction prostaglandin Luche reduction hirstutene Stryker reduction hirstutene Barton-McCombie deoxygenation and tin-free variant hirstutene and Barton decarboxylation handout # 3 Diazene-mediated deoxygenation Reductive amination saframycin A Hydrosilation reactions sparteine Radical dehalogenation reactions Clemmensen reduction see handout # 3 Woff-Kishner reduction Birch reduction

Organometallic coupling reactions - Also See Handout # 2 Stille coupling Heck coupling general Suzuki coupling discussion, Sonogashira coupling illustrated by Negishi coupling several syntheses Tsuji-Trost coupling Pd- Pt- & Au-mediated cycloisomerisations Buchwald-Hartwig coupling virantmycin xanthatin Pd-mediated carbonylation xanthatin Carbene C-H insertion reactions tetrodotoxin Hydrozirconation N1999A2 Hydroformylation SCH 351448

Other key ring-forming reactions Robinson annulation Fischer indole synthesis strychnine Pictet-Spengler reaction saframycin A Dieckmann condensation strychnine

Other reactions at carbonyl groups Schiff base formation various

Other reactions at carboxylic acids, esters, or amides Fischer esterifications trivial Amide couplings with DCC / EDC / HATU etc. N1999A2 Acid chloride / fluoride formation virantmycin prostaglandin / Iodolactonization / selenolactonization hirstutene

Other reactions at or alkyl halides Metal-Halogen exchange reactions Mitsunobu reaction sparteine Finkelstein reaction sparteine

Other reactions at aromatic rings Electrophilic aromatic substitution Nucleophilic aromatic substitution Sandmeyer reaction

Ring expansions and contractions Favorskii rearrangement Beckmann rearrangement / Photo-Beckmann sparteine Tiffeneau-Demjanov rerrangement Schmidt reaction

Notable rearrangements Curtius rearrangement virantmycin Pinacol rearrangement Prins-pinacol rearrangement problem set # 2 [2,3] Wittig rearrangement Nazarov reaction Bergman rearrangement N1999A2

Miscellaneous reactions Asymmetric hydroboration zincophorin Oxymercuration / demurcuration Simmons-Smith Carbene / carbenoid cyclopropanation zincophorin Asymmetric cyclopropanation Krapcho decarboxylation virantmycin Strecker amino acid synthesis saframycin A Corey-Fuchs reaction N1999A2 Glaser reaction N1999A2 Schmidt reaction sparteine

Appendix Ib: Other stuff you should be learning along the way.

Protecting Groups – see Greene for many others. TBS TBDPS (and selective removal in presence of TBS) TiPS (and selective removal in presence of TBS) TES TMS (and lability thereof) Bn Bz PMB (and removal under oxidative conditions) Ac MOM trimethylsilylethyl esters and carbamates CBZ Boc Fmoc (and gentle removal under basic conditions) acetal / ketal protecting groups thioacetal / thioketal protecting groups (and use as ‘umpolung’ nucleophiles THP Esters as protected carboxylic acids Protected alcohols as good, unreactive precursors to aldehydes, esters or acids Pivalates

Some other useful reagents DCC / EDC / HATU etc. Carbonyl diimidazole Weinreb amides (for mono-addition to carbonyls) Various ligands for Pd coupling (BINAP, DPPF, dba, etc.) Various bases (Hünig’s base, DBU,etc.) Higher-order cuprates, Gilman reagents, etc. Lawesson’s reagent AIBN Sulfur ylides for cyclopropanation DPPA for initiating Curtius rearrangements Cyanuric fluoride / oxalyl chloride, thionyl chloride, etc. for making acyl halides Grubbs’ catalysts Amino-acids as useful chiral building blocks Carbohydrates as useful chiral building blocks Hypervalent iodine reagents Admix / TBAF, buffered TBAF, HF-pyridine, etc. for removing silyl groups Nucleophilic catalysts (DABCO, DMAP) LiH2NBH3 for reducing amides  alcohols LiCl / LiBr as very gentle Lewis acids for enhancing reactivity Stryker reagent

Vocabulary Key intermediate Synthetic equivalent Total synthesis vs. semi-synthesis Oxidative addition Reductive elimination Transmetallation Metathesis Migratory aptitude Syn elimination Enantiselective Diastereoselective Epimerization

Useful Concepts Retrosynthetic analysis Nucleophiles and electrophiles = HOMO + LUMO Hard and soft nucleophiles and electrophiles Woodward-Hoffmann rules Indole addition to 3- or 2-position Substructure recognition Formation of oxonium ions and synthetic utility thereof Formation of imines and synthetic utility thereof Catalytic cycles Electron counting Use of crown ethers in synthesis Ways you know to control relative stereochemistry Aldol reactions (E/Z enolate  1,2-anti/syn product) Local steric control (esp. approach of nucleophiles or enolates), particularly in rings Geometric approach of reacting groups (esp. with respect to nitrene insertion reactions) Stereospecific transformations from stereochemically “fixed” substrates (Curtius rrgmt, etc.) Inversion reactions (SN2, Mitsunobu, opening, etc.) Tsuji-Trost couplings (double inversion = retention) Various ways to make E/Z olefins “Chirality transfer” in sigmatropic rearrangement reactions (esp. Ireland-Claisen) Ways you know to control absolute stereochemistry Asymmetric Diels-Alder CBS reduction Asymmetric epoxidations (Sharpless, Jacobsen, Shi) Asymmetric dihydroxylation (Sharpless) Asymmetric acylations (Evans, Carreira, organocatalytic) Asymmetric alkylation (Myers) Pd coupling strategies with chiral ligands (esp. Suzuki, Heck) Desymmetrization reactions (e.g. by enzymatic hydrolysis) Hydroboration with chiral boranes (e.g. IPC2BH) Asymmetric cyclopropanation (e.g. Charette, or diazo w/ chiral Ru) Appendix II: Syntheses

1. Strychnine Woodward, 1954 Classics I, 21 (also see: J. Am. Chem. Soc. 2001, 123, 9324)

Reactions: · Fischer indole synthesis · Indole addition · Dieckmann condensation · Allylic rearrangement

Concepts: · Retrosynthesis · Substructure recognition 2. Progesterone Handout #1: Oxidation Marker, 1944

Reactions: · Oxidative degredations, including · General metal oxide degradations · Lemieux-Von Rudloff oxidation · Ozonolysis · Jones oxidation

Concepts: · Semisynthesis · Commercial synthesis 3. Prostaglandin E2 Corey, 1969 and onward Classics I, 65

Reactions: · General discussion of olefin-forming reactions, including: · Wittig reaction · Horner-Wadsworth Emmons reaction · Still-Gennari olefination · Julia olefination · Corey-Winter olefination · Peterson olefination · Barton extrusion reaction · Asymmetric Diels-Alder reaction · Baeyer-Villiger oxidation · CBS reduction · Iodolactonization

4. Periplanone B Still, 1979 Classics I, 211

Reactions: · Anionic oxy-Cope · Rubottom oxidation · Selective epoxidations 5. Palladium-Mediated Coupling Strategies Handout #2: Palladium Coupling parts of various syntheses will be used to illustrate key transformations

Reactions: · General discussion of: · Stille coupling · Heck coupling · Suzuki coupling · Sonogashira coupling · Negishi coupling · Tsuji-Trost coupling · Pd- Pt- & Au-mediated cycloisomerizations

Concepts: · Catalytic cycles – oxidative addition, reductive elimination, etc. · Increased synthetic efficiency using organometallic coupling strategies. 6. Virantmycin Back, 2004 Angew. Chemie Int. Ed.. 2001, 43, 6493

Reactions: · Buchwald-Hartwig coupling · Acid chloride / fluoride formation · Curtius rearrangement · Krapcho decarboxylation

Concepts: · Stereodivergent synthesis 7. Xanthatin Martin, 2006 Tetrahedron 2006, 62, 11437

Reactions: · General discussion of olefin metathesis: · Ring-opening metathesis · Ring-closing metathesis · Cross metathesis · Ene-yne metathesis

8. The Ene-diynes: N1999A2 Nicolaou, 1992 – Classics I, 523 Myers, 2006 – J. Am. Chem. Soc. 2006, 128, 14825.

Reactions: · Bergman cycloaromatization

N1999A2: · Swern-type oxidations · Asymmetric epoxidations · Asymmetric dihydroxylations · Amide couplings with DCC / EDC / HATU etc. · Corey-Fuchs reaction · Glaser reaction Concepts: · Synthetic planning 9. Tetrodotoxin Du Bois, 2003 J. Am. Chem. Soc. 2003, 125, 11510 (also see: Thienamycin; Classics I, 249)

Reactions: · Carbene insertion reactions · Oxidative degradations · Methylene-forming reactions · Selenoxide elimination · TPAP/NMO oxidations · Allylic oxidations 10. Hirstutene Handout #3: Reduction Curran, 1986 Classics I, 382

Reactions: · General discussion of Radical Cyclizations · Luche reduction · Stryker reduction · Ireland-Claisen rearrangement · Selenolactonization · Radical deoxygenations & decarboxylations · Barton-McCombie deoxygenation · Tin-free variant of the Barton-McCombie · Barton decarboxylation · Diazene-mediated deoxygenation Concepts: · Baldwin’s rules for radical cyclization 11. ent-Sparteine Aubé, 2002 asymmetric Org. Lett. 2002, 4, 2577.

Reactions: · General discussion of ring expansions and contractions: · Beckmann rearrangement · Favorskii rearrangement · Tiffeneau-Demjanov rearrangement · Schmidt reaction · Finkelstein reaction · Mitsunobu reaction 12. Zincophorin Meyer and Cossy, 2004 J. Org. Chem. 2004, 69, 4626.

Reactions: · Diastereoselective aldol reactions (Review) · General discussion of · General discussion of cyclopropanation strategies · Allylations and Crotylations 13. Saframycin A Myers, 1999 J. Am. Chem. Soc. 1999, 121, 10828.

Reactions: · General discussion of auxiliary-controlled additions: · Evans’ aldol · Carreira aldol · Pseudoephedrine glycinamide alkylation · Pictet-Spengler reaction · Strecker reaction · Reductive amination 14. Endriandric Acids Nicolaou, 1982 Classics I, 264.

Reactions: · Electrocyclic Ring-Closing reaction Concepts: · Woodward-Hoffmann rules