An improved synthesis of ethyl cis-5-iodo-trans-2-methylcyclohexanecarboxylate, a potent attractant for the Mediterranean fruit fly
作者:Ashot Khrimian、Armenak Kh. Margaryan、Walter F. Schmidt
DOI:10.1016/s0040-4020(03)00853-6
日期:2003.7
Both racemic ethyl 5-iodo-2-methylcyclohexanecarboxylate (1), known as Mediterranean fruit fly attractant ceralure B1, and its (−)-(1R,2R,5R) enantiomer 1a were conveniently synthesized from commercially available racemic trans-6-methyl-3-cyclohexenecarboxylic acid 2 or its (1R,6R) enantiomer 2a. Key steps included an asymmetric Diels–Alder reaction using a sultam auxiliary and cyclization of the unwanted
由商业上可得到的外消旋反式方便地合成了外消旋的5-碘-2-甲基环己烷甲酸乙酯(1)(称为地中海果蝇引诱剂B 1)及其(-)-(1 R,2 R,5 R)对映体1a -6-甲基-3-环己烯羧酸2或其(1 R,6 R)对映异构体2a。关键步骤包括使用磺胺助剂进行不对称Diels-Alder反应,以及将不需要的反式-5-碘-反式-2-甲基环己烷羧酸环化(8)至中间体内酯7(或8a至7a)。新方法可能会绕过色谱分离,并且似乎可以扩大规模。