Experimental demonstration of base-catalyzed interconversion of isomeric betaine intermediates in the Corey-Chaykovsky epoxidation

被引：21

作者：

Edwards, David R. ^{[1
]}

Du, Jenny ^{[1
]}

Crudden, Cathleen M. ^{[1
]}

机构：

[1] Queens Univ, Dept Chem, Kingston, ON K7M 3N6, Canada

来源：

ORGANIC LETTERS | 2007年 / 9卷 / 12期

关键词：

D O I：

10.1021/ol070875j

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

The collapse of hydroxysulfonium salts has been examined as a model for the epoxidation of aldehydes. The anti diastereomer reacted with retention of stereochemistry and no crossover, while the syn diastereomer gave crossover products along with cis and trans epoxides. Deprotonation and reprotonation on the carbon of the alpha-hydroxy sulfonium ylide is presumed responsible for production of the trans epoxide. This reaction pathway has been proposed to explain losses of enantioselectivity but never directly observed.

引用

页码：2397 / 2400

页数：4

共 18 条

[1] Asymmetric sulfonium ylide mediated cyclopropanation: Stereocontrolled synthesis of (+)-LY354740
Aggarwal, VK
Grange, E
[J]. CHEMISTRY-A EUROPEAN JOURNAL, 2006, 12 (02) : 568 - 575
[2] Highly enantioselective synthesis of glycidic amides using camphor-derived sulfonium salts. Mechanism and applications in synthesis
Aggarwal, VK
Charmant, JPH
Fuentes, D
Harvey, JN
Hynd, G
Ohara, D
Picoul, W
Robiette, R
Vasse, JL
Winn, CL
[J]. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2006, 128 (06) : 2105 - 2114
[3] Carboxylate-stabilised sulfur ylides (thetin salts) in asymmetric epoxidation for the synthesis of glycidic acids. Mechanism and implications
Aggarwal, VK
Hebach, C
[J]. ORGANIC & BIOMOLECULAR CHEMISTRY, 2005, 3 (08) : 1419 - 1427
[4] Catalytic, asymmetric sulfur ylide-mediated epoxidation of carbonyl compounds: Scope, selectivity, and applications in synthesis
Aggarwal, VK
Winn, CL
[J]. ACCOUNTS OF CHEMICAL RESEARCH, 2004, 37 (08) : 611 - 620
[5] The complexity of catalysis: origins of enantio- and diastereocontrol in sulfur ylide mediated epoxidation reactions
Aggarwal, VK
Richardson, J
[J]. CHEMICAL COMMUNICATIONS, 2003, (21) : 2644 - 2651
[6] Unraveling the mechanism of epoxide formation from sulfur ylides and aldehydes
Aggarwal, VK
Harvey, JN
Richardson, J
[J]. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2002, 124 (20) : 5747 - 5756
[7] Additions of stabilised and semi-stabilised sulfur ylides to tosyl protected imines: Are they under kinetic or thermodynamic control?
Aggarwal, VK
Charmant, JPH
Ciampi, C
Hornby, JM
O'Brien, CJ
Hynd, G
Parsons, R
[J]. JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 1, 2001, (23): : 3159 - 3166
[8] Aggarwal VK, 2001, ANGEW CHEM INT EDIT, V40, P1433, DOI 10.1002/1521-3773(20010417)40:8<1433::AID-ANIE1433>3.0.CO
[9] 2-E
[10] AGGARWAL VK, 1997, J CHEM SOC, V1, P2811

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