Synthesis of (5R)-(Z)-6-(1-methyl-1,2,3-triazol-4-ylmethylene)penem-3-carboxylic acid, a potent broad spectrum β-lactamase inhibitor, from 6-aminopenicillanic acid
作者:Neal F. Osborne、Richard J. Atkins、Nigel J. P. Broom、Steven Coulton、John B. Harbridge、Michael A. Harris、Irene Stirling-François、Graham Walker
DOI:10.1039/p19940000179
日期:——
(5R)-(Z)-6-(1-Methyl-1,2,3-triazol-4-ylmethylene)penem-3-carboxylic acid 34 (BRL 42715) has been prepared from 6-aminopenicillanic acid 4 (6-APA) by a short, stereoselective and efficient route via the novel intermediate. p-methoxybenzyl (5R,6S)-6-bromopenem-3-carboxylate 17.Elaboration of 6-APA 4 to the azetidinone disulfide 10 by established methodology, followed by reductive formylation provided the crystalline C-4 formylthio-azetidinone derivative 29. Cyclization of the oxalimide 28, obtained by ozonolysis of the formylthio derivative 29. to the crystalline 6 alpha-bromopenem ester 17 was effected by way of the phosphite-mediated carbonyl-carbonyl coupling reaction.
(5R)-(Z)-6-(1-甲基-1,2,3-三唑-4-基亚甲基)青霉烷-3-羧酸 34 (BRL 42715) 是通过一种简短、高立体选择性和高效的路线从 6-氨基青霉烷酸 4 (6-APA) 制备而来的,该路线利用了新型中间体 p-甲氧基苄基 (5R,6S)-6-溴青霉烷-3-羧酸盐 17。将 6-APA 4 通过已建立的方法制备成叠氮杂环酮亚砜 10,随后通过还原甲酰化得到结晶 C-4 甲酰巯基叠氮杂环酮衍生物 29。通过臭氧解将叠氮杂环酮亚砜 29 转化为草酰亚胺 28,然后在磷酸酯介导的酮-酮偶联反应中,将草酰亚胺 28 环化成结晶 6-α-溴青霉烷酯 17。