Efficient and practical synthesis of 1⊝methylcarbapenems
摘要:
An efficient and practical method of synthesizing 1 beta-methylcarbapenem, S-4661, was developed. (4R)-4-[(1S)-1-Methylallyl]-2-azetidinone, 2, prepared stereoselectively from commercially available acetoxy-azetidinone 3, was converted to the beta-keto ester 6 in four steps. The iodonium ylide 5 was prepared from 6, then cyclized to obtain the bicyclic beta-keto ester 4. Finally, 4 was processed to the target product, S-4661, by conventional procedures. (C) 1997, Elsevier Science Ltd.
Efficient and practical synthesis of 1⊝methylcarbapenems
摘要:
An efficient and practical method of synthesizing 1 beta-methylcarbapenem, S-4661, was developed. (4R)-4-[(1S)-1-Methylallyl]-2-azetidinone, 2, prepared stereoselectively from commercially available acetoxy-azetidinone 3, was converted to the beta-keto ester 6 in four steps. The iodonium ylide 5 was prepared from 6, then cyclized to obtain the bicyclic beta-keto ester 4. Finally, 4 was processed to the target product, S-4661, by conventional procedures. (C) 1997, Elsevier Science Ltd.
Novel and efficient synthesis of 1β-methylcarbapenems utilizing cyclization of hypervalent iodonium ylides
作者:Masaharu Kume、Tadatoshi Kubota、Yasuyoshi Iso
DOI:10.1016/0040-4039(95)01703-k
日期:1995.10
lβ-Methylcarbapenems were efficiently synthesized utilizing acid- and rhodium(II)-catalyzed cyclization of iodoniumylide intermediates, which were easily prepared from the corresponding β-keto ester derivatives.