Reagents for Alkylidenations
O
Jinglong Chen Feb. 2, 2005 Farewell the Monkey Year Welcome the Rooster Year 1 C=O Bond Cleavage Reactions
C(sp3) Dialkylation Reetz ( Ti ), Tani ( Zn/V ), Mole (Al) C(sp3)
2 Dialkenylation C(sp ) Schonberg ( Mg ) Xi ( Zr/Al ), Xi ( Li ) C(sp2) O
Dialkynylation C Unknown C
Olefination Wittig-type ( P), Julia (S) , Peterson (Si), Nysted (Zn), C Grubbs ( Ti ), McMurry ( Ti, Zn), Tebbe ( Ti ), Petasis ( Ti ), Takeda ( Ti ), Takai ( Ti, Zn ) 2 Dialkylation
C(sp3) Dialkylation Reetz ( Ti ), Tani ( Zn/V ), Mole (Al) C(sp3)
2 Dialkenylation C(sp ) Schonberg ( Mg ) Xi ( Zr/Al ), Xi ( Li ) C(sp2) O
Dialkynylation C Unknown C
Olefination Wittig-type ( P), Julia (S) , Peterson (Si), Nysted (Zn), C Grubbs ( Ti ), McMurry ( Ti, Zn), Tebbe ( Ti ), Petasis ( Ti ), Takeda ( Ti ), Takai ( Ti, Zn ) 3 Dialkylation
OO OO 1. EtLi 77% 2. CH3TiCl3/(CH3)2TiCl2 O
Reetz, M. T. et. al. J. Org. Chem. 1983, 48, 254 O
Br VCl2(TMEDA)2/Zn + R.T. to Reflux 59-84%
Tani, K. et. al. J. Org. Chem. 1997, 62, 8109
O
AlMe3 50% 17 h, 180 oC, PhCl
Mole, T. et. al. JCS. Chem. Comm. 1972, 595
4 Dialkenylation
C(sp3) Dialkylation Reetz ( Ti ), Tani ( Zn/V ), Mole (Al) C(sp3)
2 Dialkenylation C(sp ) Schonberg ( Mg ) Xi ( Zr/Al ), Xi ( Li ) C(sp2) O
Dialkynylation C Unknown C
Olefination Wittig-type ( P), Julia (S) , Peterson (Si), Nysted (Zn), C Grubbs ( Ti ), McMurry ( Ti, Zn), Tebbe ( Ti ), Petasis ( Ti ), Takeda ( Ti ), Takai ( Ti, Zn ) 5 Dialkenylation
O Ph Ph PhMgBr
S S S Benzene,Reflux, overnight S S S 20% Schonberg, A. et. al. J. Am. Chem. Soc. 1946, 609
O ZrCp2 and AlMe3 H H 50~70%
Xi, Z. et. al. Angew.Chem. Int. Ed. 2000, 39, 2950
Li Li
O 75%
Xi, Z. et. al. Angew.Chem. Int. Ed. 2001, 40, 1913 6 Dialkynylation—Opportunity
C(sp3) Dialkylation Reetz ( Ti ), Tani ( Zn/V ), Mole (Al) C(sp3)
2 Dialkenylation C(sp ) Schonberg ( Mg ) Xi ( Zr/Al ), Xi ( Li ) C(sp2) O
Dialkynylation C Unknown C
Olefination Wittig-type ( P), Julia (S) , Peterson (Si), Nysted (Zn), C Grubbs ( Ti ), McMurry ( Ti, Zn), Tebbe ( Ti ), Petasis ( Ti ), Takeda ( Ti ), Takai ( Ti, Zn ) 7 Olefination C(sp3) Dialkylation Reetz ( Ti ), Tani ( Zn/V ), Mole (Al) C(sp3)
2 Dialkenylation C(sp ) Schonberg ( Mg ) Xi ( Zr/Al ), Xi ( Li ) C(sp2) O
Dialkynylation C Unknown C
Olefination Wittig-type ( P), Julia (S) , Peterson (Si), Nysted (Zn), C Grubbs ( Ti ), McMurry ( Ti, Zn), Tebbe ( Ti ), Petasis ( Ti ), Takeda ( Ti ), Takai ( Ti, Zn )
8 Olefination (Alkylidenation)—Hot Field
1. sp3-Geminated Organodimetallic Reagents:
¦Ä_ 2 1 _ M O M O M1 ¦Ä M2 1 2 O M M + C C _ C C ¦Ä+ ¦Ä + _ ¦Ä ¦Ä C C
2. Metallacarbene or Carbene-like Species:
¦Ä_ + ¦Ä M O M O M O
+ C C C C ¦Ä+ ¦Ä_ C C
Schrock Carbene Or Carbene-like Species 9 sp3-Geminated Organodimetallic Reagents
1. Li/Mg, Li/Ti: O OH Ph Ph Ph PhO2S Ph H + PhO2S Ph PhO S Li Li 2 Ph Major Minor
MgI2 O Ph PhO2S Ph Ph H 70% IMg Li PhO2S Ph
Umani-Ronchi, A. et. al. J. Chem. Soc. Perkin Trans. I 1973, 1166
O
PhO2S 73% + 1. eq. Cl2Ti(OiPr)2 PhO S Li Li 2
Gais, H. J. et. al. Angew. Chem. Int. Ed. 1985, 24, 610
10 sp3-Geminated Organodimetallic Reagents
2. Mg: O H H Ph Me3Si Ph Ph 80% BrMg MgBr Me3Si Ph
Bertini. F. et. al. Tetrahedron 1970, 26, 1281
3. Al: O H R = Et 9% C H H Ph 5 11 Ph Ph R = Cl 71% R = Cl, Et 51% R2Al AlR2 C5H11 Ph
Eisch, J. J. et. al. J. Org. Chem. 1988, 53, 2829
11 sp3-Geminated Organodimetallic Reagents
4. B/Li: O H Ph Ph Heptyl H HPh HO Ms BLi 2 Heptyl H Heptyl 40% E 40%
Pelter, A. et. al. Tetrahedron Lett. 1983, 24, 635
5. B/Cu,Zn: O H Ph H HPh H O B Cu(CN)ZnI BF3 H O 70% H H O Ph B O OBF2
Miyarua, N. et. al. Tetrahedron 1996, 52, 915 12 sp3-Geminated Organodimetallic Reagents
6. Zr/Zn:
O ZrCp Ph 2 HPh Cl 83% Zn BF3 H
Knochel, P. et. al. J. Am. Chem.Soc. 1991, 113, 9888
7. Zn: O Br Zn HC11H23 CH2 O Zn 85% HC11H23 Zn BF3 Br
Matsubara, S. et. al. Synlett 1998, 313 Nysted Reagent US Pat. (1975) 13 sp3-Geminated Organodimetallic Reagents
8. Cr:
O I III C H H CrCl -DMF Cr HMe 5 11 C H CH 2 5 11 C5H11 CH C C THF I CrIII BF3 H Me 94% E/Z=96/4
Takai, K.; Utimoto, K. et. al. JACS. 1987, 109, 951
Takai-Utimoto Reaction
14 sp3-Geminated Organodimetallic Reagents
9. Li/Si:
OTES O O MeO OMe 1. LiCH2SiMe3 MeO OMe 2. DDQ, THF Me NNMe Me NNMe OMe O
Mitomycin Congeners Danishefsky, S.J. et. al. J. Org. Chem. 1988, 53, 3391.
Peterson Olefination JOC (1968) 15 sp3-Geminated Organodimetallic Reagents 10. Li/S:
R CHO R
R 1. TBSO OTBS Na-Hg OBz SO Ar 2. BzCl 2
Li SO2Ar TBSO OTBS TBSO OTBS
(+)-Himbacin Hart, D. and Kozikowski A.P. et. al. JOC, 1997, 62, 5023
Julia Olefination TL (1973) 16 11. Ti: CHO
O BnO OHC O OBn O O
TiCl4, Zn-Cu, DME 59%
O BnO O OBn O O
Archaeal 72-Membered Macrocyclic Tetraether Lipids Kakinuma, K. et. al. J. Org. Chem. 1998, 63, 2689
Ti Ti Ti Ti O 2 OO OO OO O O
17 Wittig and Horner-Wittig Reactions
12. P: O H H H H H PhLi Ph H + _ PPh3 Ph Ph Ph PPh3 I Ph 82%, 70% Z Wittig, G. et. al. Chem. Ber. 1954, 87, 1318
O Ph H Li H H H RLi Ph H OH Ph PPh2 Ph PPh Ph PPh2 2 Ph Ph O O O Clayden, J. et. al. Angew. Chem. Int. Ed. Engl. 1996, 35, 241
18 Why use Titanium-based Reagents?
1. Non-basic, reactive reagent
2. More reactive to the sterically hindered carbonyl group
19 Comparison of Tebbe and Wittig Reagents
TebbeWittig
O 97% 89%
O 77% 4%
O Ph Ph 63% 38%
Ph Ph
Pine, S. H.; Shen, G. S., Hoang, H. Synthesis, 1991, 165
20 Why use Titanium-based Reagents ?
1. Non-basic, reactive reagent
2. More reactive to the sterically hindered carbonyl group
3. Alkylidenate carboxylic acid and carboxylic acid derivatives
P(OEt)3 Ti Ti Me Zn, TiCl4, P(OEt)3 Cl Ti TMEDA, PbCl (cat), Ti Al Me 2 + RCHBr Cl 2 Cl Takai Ti RS SR Petasis Reagent Reagent Tebbe Reagent R1 R2 Grubbs Reagent Takeda Reagent
21 Citing Articles--Summary
OLEFIN HOMOLOGATION WITH TITANIUM METHYLENE-COMPOUNDS TEBBE FN, PARSHALL GW, REDDY GS JOURNAL OF THE AMERICAN CHEMICAL SOCIETY100: 3611- 3613 1978 These documents in the database cite the above record: 623 results found Go to Page: of 63 Records 1 -- 10 [ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 ] Use the checkboxes to select individual records for marking, then click Submit to add them to the Marked List. 1. Eyrisch KK, Muller BKM, Herzig C, et al. Ethenolysis of functionalized cycloolefins DESIGNED MONOMERS AND POLYMERS 7 (6): 661-676 2004 Times Cited: 0
2. Korotchenko VN, Nenajdenko VG, Balenkova ES, et al. Olefination of carbonyl compounds. Modern and classical methods USPEKHI KHIMII 73 (10): 1039-1074 2004 Times Cited: 0
3. Yan TH, Tsai CC, Chien CT, et al. Dichloromethane activation. Direct methylenation of ketones and aldehydes with CH2Cl2 promoted by Mg/TiCl4/THF ORGANIC LETTERS 6 (26): 4961-4963 DEC 23 2004 Times Cited: 1
22 Tebbe Reagent
Without Base
O R Cl R R R Ti Al Ti O Cl Cl Cl Al
+ Cp2TiMeCl+ (MeAlO)n RR
Hughes, D. L. et. al. Organometallics 1996, 63, 2689
23 Tebbe Reagent
In the presence of base
O Cl Pyridine R Ti Al Ti CH R O R 2 Ti Cl Cl R
+ Ti O RR
Hughes, D. L. et. al. Organometallics 1996, 63, 2689 24 Tebbe Reagent with Ketone and aldehyde
O Tebbe, PhMe 71% O O O O O EtO O EtO
Didemnenones Winterfeldt, E. et. al. JCS. Pekin Trans I 1994, 3525
O CHO O MOM MOM O N Tebbe,THF 65% O N MeN MeN
CH2OH CH2OH
Fukuyama, T. et. al. Pure Appl. Chem. 1997, 69, 501 25 Tebbe Reagent: Esters and Lactones
Me OTBDMS Me OTBDMS
Tebbe,THF 61-85%
CO TBDMS CO2Me CO2TBDMS 2 MeO
Atrochrysone Steglich, W. et. al. JCS. Pekin Trans I 2000, 2483
O O O O Tebbe,THF/PhMe O 69% O O O O O O O O
Polyhydroxylated Molecules Sinay, P. et. al. TL 1994, 2537
26 Tebbe Reagent: Thioesters, Amids and Carbonates
Tebbe 25%
S S O
Tebbe 70%
S O
O Tebbe,THF/PhMe O Tebbe,THF/PhMe 97% 56% O O O O N(Me)Ph N(Me)Ph
Hartley, R. C. et. al. JCS, Perkin Trans. I 2002, 2763 and references therein. 27 Tebbe Reagent: Acid Chlorides and Enol ethers
TiClCp O Cp Ti O 2 Tebbe 2 O
RCl Cl R R
TiClCp Cp Ti O 2 Tebbe 2
1 OR1 ROR R R
CHO 55-78% Ph
OH
RPh
Hanzawa, Y.; and Taguchi, T. et. al. Tetrahedron 1998, 1138728 Tebbe Reagent: Alkenes
Cp2TiCl2 (2.8 eq) AlMe3 (7.8 eq) O
O O Cp2TiCl2 (6 eq) AlMe3 (12 eq) O
O TiCp2
Aplysins Harrowven, D. C. et. al. Tetrahedron 2001, 791
29 Summary of the Tebbe Reagent
Tebbe methylenation of esters has been accomplished in the presence of many functional groups. Alkenes including dienes, Vinyl fluorides, vinyl chlorides, aryl bromides, and aryl iodides Ethers including benzyl,and trityl ethers, Silyl ethers including TMS,TBDMS,and di-tertbutylsilylene, Acetals including benzylidene acetal,MOM, and acetonides Selenoglycosides and thioglycosides Carbamates including NHBoc,and sulfonamides The key advantage of the Tebbe reagent over other titanium reagents used in alkylidenations is that the reactive titanium methylidene is generated and reacted at low temperature.
Its disadvantages are its high sensitivity to both moisture and air, its Lewis acidic character, and the fact that it is limited to methylenation.
30 Petasis Reagent: Aldehydes
THF or Toluene Ti Ti CH2 α-elimination
Petasis, N. A. et. al. J. Am. Chem. Soc.1990, 6392 H HO H H N O N O O Petasis, THF O 87%
N N O O
21-oxogelsemine Hart, D. J. et. al. J. Am. Chem. Soc.1990, 6392
O Petasis (2.5 eq.) THF O Ph 52% Ph O N O N MeO C MeO C 2 CHO 2
α-Alkyl-α-amino Acids Hegedus, L. S. JOC 1993, 5918 31 Petasis Reagent: Ester and Lactones
Petasis (3 eq.) THF 73% OO O OO O
HO Petasis (1.5 eq.) THF ¦¤ H 70% O O OMe OMe EtO C Me EtO2C Me 2
O Petasis THF ¦¤ 65% Ph Ph
OEt OEt
O Ph Petasis PhMe ¦¤ Ph 62% O O
Hartley, R. C. et. al. JCS, Perkin Trans. I 2002, 2763 and references therein. 32 Petasis Reagent: β-Lactones
C H C H C11H23 C6H13 11 23 Petasis (3 eq.) THF ¦¤ 6 13 20% OO OO O O O t But NHCHO Bu NHCHO
Orlistat Howell, A. R. et. al. Bioorg. Mol. Chem. Lett. 1998, 977
33 Petasis Reagent: Thioesters, Selenoesters, Acylsilanes, Carbonates, and Lactams
O Petasis, PhMe, ¦¤ O Petasis, PhMe, ¦¤ 70% 77% SPh SPh Me SePh SePh
O Petasis, PhMe, ¦¤ 77%
H3C(H2C)8 SiMe3 H3C(H2C)8 SiMe3
Petasis, THF, ¦¤ O O 72% O O O
Petasis (1.4 eq.) t t PhMe, Pyridine, ¦¤ Bu Me 2SiO Bu Me2SiO 40-50% N NO CO2Me CO2Me
Hartley, R. C. et. al. JCS, Perkin Trans. I 2002, 2763 and references therein 34 Petasis Reagent: β-Lactams and α-Lactams
Ph Petasis (1.5 eq.) PhMe ¦¤ Ph N 63% N O
Petasis (1.5 eq.) PhMe ¦¤ 56% N N
O
OTBDMS Petasis (5 eq.) PhMe ¦¤ OTBDMS O 81% O
N N AcO Boc AcO Boc
Hartley, R. C. et. al. JCS, Perkin Trans. I 2002, 2763 and references therein.
35 Petasis Reagent: Imides, and Acid anhydrides
O Petasis, PhMe ¦¤ 75% NMe NMe + NMe
O O
1.5 eq. Petasis 1 : 0 4.0 eq. Petasis 1 : 20
O Petasis, THF, ¦¤ O 70% O O + O
O 1 eq. Petasis 10 : 1 2 eq. Petasis 2 : 1 4 eq. Petasis 0 : 1
Hartley, R. C. et. al. JCS, Perkin Trans. I 2002, 2763 and references therein. 36 Petasis’ Method for Alkylidenation
Ti
OO PhMe, ¦¤, 67% O
Cl
Ti
O Cl Cl O O PhMe, ¦¤, 100% only Z
Hartley, R. C. et. al. JCS, Perkin Trans. I 2002, 2763 and references therein.
37 Summary of the Petasis Reagent
The advantages of Petasis methylenation of carbonyl groups:
1. The stability to air and moisture of dimethyltitanocene, 2. The absence of Lewis acid from these reactions and 3. The ease of purification following reaction Titanium-containing impurities can often be precipitated and removed by simple filtration
The disadvantages
The high temperature (65°C) needed to induce elimination
38 Takeda Reaction
Mg, 2 P(OEt)3 Cp2TiCl2 Cp2Ti(P(OEt)3)2 Molecular Sieves 4A, THF, rt
O OBn H O O BnO MOMO H OBn PhS SPh
Cp2Ti(P(OEt)3)2 52-67%
O OBn H O O BnO MOMO H OBn
Takeda, T. et. al. JACS. 1997, 1127 Hirama, M. et. al. Chem. Comm. 2001, 381 39 Summary of the Takeda Reation
Advantages:
A range of alkylidenating agents that can be produced The mildness of the conditions The ease of synthesis of thioacetal substrates
Disadvantages:
The use of excess titanocene (at least 3 equiv.) and triethylphosphite (at least 6 equiv.).
40 Takai Reagent
Zn, TiCl4, TMEDA, THF 3 O HR 25 OC + R3CHBr2 R1 OR2 Zn, TiCl4, R1 OR2 TMEDA, THF O HMe 25 OC + MeCHBr2 Ph OBut Ph OBut 81% Zn, TiCl4, Z:E 100:29 TMEDA, THF HC5H11 O O n 25 C + C5H11CHBr2 Pri OMe Ph OMe 89% Z:E 100:0 Zn, TiCl4, PbCl2 TBDMSO TBDMSO O MeCHBr2, TMEDA, THF, rt, 14 h Ph OEt Ph OEt
Hartley, R. C. et. al. JCS, Perkin Trans. I 2002, 2763 and references therein. 81% 41 Z:E >98:2 Applications of the Takai Reagent
OTBDPS
O
OTBS O O
H H O
Zn, TiCl4, PbCl2 CH2I2,THF 65% OTBDPS
O
OTBS O O
H H O
Laulimalide Paterson, I. et. al. OL 2001, 213 42 Summary of the Takai Reagent
The advantage: A mild one-pot procedure that allows the alkylidenation of a range of carboxylic acid and carbonic acid derivatives with good stereoselectivity.
The disadvantage: 1,1-dibromoalkanes Methylenation is not good
43 Applications of Alkylidenation Reactions Alkylidenation-Hydrogenation
CF3 CF3
O CF3 Petasis, THF/Toluene, 80 oC O O CF3 68% O O N N Ph Ph
H2, 10% Pd/C EtOAc/iPrOH
CF3
R2 R1 CF3 1, R1= CH3, R2= H O O 2, R1= H, R2= CH3 1 : 2 = 8:1, 84% N
Ph
Human NK-1 Receptor Antagonist Hale, J. J. et. al. JMC 1998, 41, 4607 44 Methylenation-Hydroboration
OMOM OMOM MOMO OMOM Petasis, THF, Reflfux MOMO OMOM
OMOM 89% OMOM O O O H H
9-BBN (2.6) THF, reflux, 5h
OMOM OMOM H MOMO Pd(0), Base O OMOM MOMO OMOM H OMOM O B OMOM O O O H H H OOTf H
Polycyclic ether Sasaki, M. et. al. TL 1998, 39, 9027
45 Methylenation-Hydrolysis and Alkoxylation
Cp2TiMe2 H H O+ H OMe 3 O 83% O
α-Oplopenone Taber, D. F. et. al. JOC 1998, 63, 7953 OMe OMe
Cp2TiMe2,MeLi O O O O OMe O OMe
MeOH, HCl
OMe OMe allyltrimethylsilane TiCl , CH Cl O 4 2 2 O o MeO O -78 C, 79% OMe O OMe 72% 46 (+)-nemorensic acid Donohoe, T. J. et. al. CC 2000, 465 Petasis-Ferrier Reaction
O O O O N O PMBO PMBO N O Cp2TiMe2 O O 83% O
PDBTS PDBTS
Me2AlCl 89%
O O PMBO N O
Phorboxazole O Smith III, A. B. et. al. OL 1999, 909 PDBTS
47 Petasis-Ferrier Reaction
O Ph(H2C)2 O Ph(H2C)2 O Cp2TiMe2 O O THF, 86% O O Ph AlR3
Ph(H C) O 2 2 Ph(H C) O PCC, CH2Cl2 2 2
O 98% (86% syn) 96% OH
Petasis, N. A. et. al. TL 1996, 141 48 Petasis-Ferrier-like Reaction
Me OTBDMS Me OTBDMS
Tebbe,THF 61-85%
CO TBDMS CO2Me CO2TBDMS 2 MeO
i. aq. K2CO3, MeOH ii. Tf2O, DMAP (10 eq. each) CH2Cl2 40-80%
Me Me OTBDMS OH
OH OH O MeO
Atrochrysone Steglich, W. et. al. JCS. Pekin Trans I 2000, 2483
49 Tebbe-Radical Reaction
R R OBn ' OBn ' R R O Me Al-TiCp Cl BnO 3 2 2 BnO O O
OBn OBn
ClCH(CO2Et)2 Bu3SnH
R CO2Et ' OBn R H
BnO CO2Et O
OBn Analogues of Glyceroglycolipids Nicotra, F. et. al. Tetrahedron 1997, 6163 50 Tebbe-Simmons-Smith and Tebbe-D-A Reaction
OMe OMe OMe O O O i ii O
Br Br Br
i. Tebbe Reagent, pyridine, 1:3 THF/toluene. ii. CH2I2, Zn-Cu couple, I2, ether, reflux
A potential antiinflamatory Duplantier, A. J. J. et. al. JMC 1996, 39, 120
OMe OMe MeO2C OMe O Tebbe 65%
O O MeO2C O
92% i. MeO2CCO2Me
ii. DDQ
Diaryl ethers Olsen, R. K. et. al. JOC 1995, 6025 51 Petasis-Diels-Alder Reaction
H H O O OTBS Tebbe 97% O OTBS
Me Me
o K2CO3, 100 C O
58%
H O OTBS O Me
Reveromycin B Rizzacasa, M. A. et. al. JOC 1997, 1196
52 Tebbe-Claisen Reaction
OMe OMe Br Br
O Tebbe O O O O
80 oC, 82%
OMe Br
O O
Frondosin B Danishefsky, S. G. et. al. Angew. Chem.Int. Ed. 2000, 39, 761
53 Tebbe-Claisen Reaction
H H H TBSO 1. Tebbe, PyH, CH2Cl2, THF o H OBn 2. p-cymene, 120-130 C TBSO O O H OTBS O
Kalmanol Paquette, L. A. et. al. JACS 1996, 118, 727
O
o O 1. Tebbe,THF, 65 C O o n 2. decalin, 190 C n
Petasis, N. A. et. al. TL 1993, 34, 1721
54 Takai-Cope Reaction
Zn, TiCl4, PbCl2 TBDMSO TBDMSO O MeCHBr2, TMEDA, THF, rt, 14 h Ph OEt Ph OEt
81% Z:E >98:2
Bu4NF, THF, 4A MS, rt, 1h
OH HO KH, 18-crown-6, O THF, rt, 3h
Ph Ph OEt dr 11:1
Hartley, R. C. et. al. TL 1998, 39, 685
55 Tebbe-RCM Reaction R R R O Tebbe O O O
TiCp2
R R
OR O O
TiCp2 TiCp2
O O O O OBn BnO
BnO O TBSO O OBn HHH H H H
Tebbe (4 eq.), THF, 25oC,0.5h,then, reflux 71% O O O OBn BnO
BnO O O OBn HHH OTBSH H
Nicolaou, K. C. et. al. JACS 1996, 118, 1565 56 Tebbe-ROM Reaction
OtBu Tebbe or Cp2Ti
90 oC
CO2tBu
Capnellene Grubbs, R. H. et. al. JOC 1990, 55, 843
O
H i. Tebbe, DMAP H OEt ii. 90 oC iii. 1M HCl O H
Hydroindanone Harlterman, R. L. et. al. JOMC 1997, 547, 41 57 Summary
Hurry up! Please Use Tebbe and Petasis!
The End!
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