作者:Tomasz Fekner、Jack E Baldwin、Robert M Adlington、Timothy W Jones、C.Keith Prout、Christopher J Schofield
DOI:10.1016/s0040-4020(00)00486-5
日期:2000.8
Two practical routes to (6S,7S)-cephalosporins from 6-aminopenicillanic acid (6-APA) are described. In the first, 6-APA was converted to (2S,4S,5S,6S)-penicillin sulfoxide 49, which underwent Morin ring expansion to a protected (6S,7S)-cephem 50. In the second, ester 15 was converted to (2S,4S,5S,6R)-penicillin sulfoxide 58, which was then transformed into (6S,7R)-cephem 59. Different methods for the epimerisation of the C-7 position of cephem 59 were examined. (C) 2000 Elsevier Science Ltd. All rights reserved.