Premium
1,3‐Chirality Transfer by Fragmentation of Allylsulfinic Acids: A Diastereoselective Approach to Vinyl Bromides Related to trans ‐Hydrindane or trans ‐Decalin
Author(s) -
Chochrek Paweł,
Wicha Jerzy
Publication year - 2007
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200700006
Subject(s) - chemistry , allylic rearrangement , substituent , organic chemistry , medicinal chemistry , bromine , sodium borohydride , catalysis
Diastereoselective approaches to vinyl bromides from bromoallylic alcohols by fragmentation of the respective allylsulfinic acids have been investigated. Bromoallylic alcohols 1a and 6 were transformed into the respective 1,3‐benzothiazol‐2‐yl sulfides 2a and 7 by the Mitsunobu inversion reaction under modified conditions. The sulfides were then oxidized into sulfones 11a and 12a , respectively. Reduction of 11a and 12a with sodium borohydride gave the respective allylsulfinic acid salts 13a and 15 which, without isolation, were treated with aqeous tartaric acid. The salt 13a gave exclusively 5α‐cholestane derivative 14a whereas 15 provided a mixture of the 5α and 5β derivatives 16 and 17 (after deprotection), the former prevailing. In an alternative approach, benzothiazolyl sulfides 2a and 7 were treated sequentially with BH 3 · THF and LiAlH 4 to give thiols 18a and 19a , respectively. Oxidation of thiols 18a and 19a with oxaziridine 21 gave the respective sulfinic acids which, on gentle heating, afforded bromoolefins 14a and 22a , respectively, as the only products. Analogous reaction sequences starting from allylic alcohols devoid of the bromine substituent 1b and 8 have also been studied.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)