Tetrahedron p. 1313 - 1324 (1984)
Update date:2022-08-05
Topics: Thiols Racemization α-Alkylation Carboxylic Acids Tertiary alcohols
Seebach, Dieter
Naef, Reto
Calderari, Giorgio
α-Hydroxy- and α-mercapto-carboxylic acids are condensed with pivalaldehyde to give 2-t-butyl-5-substituted-1,3-dioxolanones or 1,3-oxathiolanones (2); the predominate cis-isomers are separeted by crystallization.The cis-disubstituted heterocycles 2 derived from lactic, mandelic and malic acid funish, after deprotonation with LDA, reaction with electrophiles such as alkyl halides, aldehydes and ketones, and hydrolysis α-branched α-hydroxy-carboxylic acids (3, 6, 8, 9, 10).These result from an overall substitution of the proton in the α-CO position with retention of configuration.The optically active carboxylic acids are α-alkylated without racemization and without employment of a chiral auxiliary ("self-reproduction of chirality", Scheme 1).The diastereoselectivities (ds) are generally >95percent (Table 1, 2, and 20-25).
View MoreRefine Chemicals Science & Technology Technology Developing Co., Ltd.
Contact:+86-22-87899130
Address:No.12,west keyan road,Tianjin City
Guilin Zhenda Bio-Tech Co., Ltd.
Contact:86-773-3568977
Address:-Yangtang shangshui industry park, Lingui county,
Hangzhou Yanshan Chemical Co.,Ltd.
Contact:86-571- 87698076
Address:Room 1001, #1 Building, Zhongtian MCC, No.2 Youzhinong, Wenyi West Road, Xihu District, Hangzhou, China
Guangzhou Reachin Chemical Co., Ltd
Contact:+86-20-37087379 ext.604
Address:A122C-1, Tianyuan Plaza, 401 Tianyuan Rd., Tianhe, Guangzhou, China
Anhui New Star Pharmaceutical Development Co., Ltd
Contact:013956922763
Address:Floor 3, F9A, F Workshop, No.110 Kexue Road, High-Tech Development Zone, Hefei, Anhui ,China
Doi:10.1016/S0040-4039(00)85025-X
(1986)Doi:10.1016/S0040-4039(00)84579-7
(1986)Doi:10.1039/c9cc09216a
(2020)Doi:10.1021/om00149a019
(1987)Doi:10.1248/cpb.39.1902
(1991)Doi:10.1007/s11172-007-0233-7
(2007)