Total Synthesis of Cristatic Acid Based on Late-Stage Decarboxylative Allylic Migration and Biomimetic Aromatization of a Diketo Dioxinone
作者:Nicolas S. George、Katie E. Anderson、Anthony G. M. Barrett
DOI:10.1002/ejoc.201301102
日期:2013.11
A fifteen-step synthesis of methyl cristatate is described. tert-Butyl-[(E)-6-iodo-3-methylhex-2-enyloxy)]diphenylsilane, synthesized from geraniol, was coupled with 2-(diethoxymethyl)-4-lithiofuran and transformed – by acetal hydrolysis, Wittig olefination, and desilylation – into a sesquiterpene furan alcohol. This alcohol was converted into methyl cristatate by sequential condensation with carbonyldiimidazole
描述了一个十五步合成的甲基锍酸甲酯。由香叶醇合成的叔丁基-[(E)-6-iodo-3-methylhex-2-enyloxy)]二苯基硅烷与 2-(二乙氧基甲基)-4-硫呋喃偶联并通过缩醛水解、Wittig 烯化、和脱甲硅烷基化——变成倍半萜呋喃醇。通过与羰基二咪唑和衍生自 2,2-二甲基-6-(2-氧代丙基)-4H-1,3-二恶英-4-one 的烯醇二价阴离子以及随后的 Pd0 催化脱羧烯丙基的顺序缩合,该醇转化为甲基丙烯酸甲酯迁移、仿生芳构化和与甲醇的酯交换。