Addition of silyloxydienes to 2,6-dibromo-1,4-benzoquinone: an approach to highly oxygenated bromonaphthoquinones for the synthesis of thysanone
作者:David Barker、Margaret A Brimble、Peter Do、Peter Turner
DOI:10.1016/s0040-4020(03)00291-6
日期:2003.3
when benzene was used. Naphthoquinone 6a underwent benzylation to naphthoquinone 6c. Addition of 1,1-dimethoxy-3-trimethylsilyloxy-1,3-butadiene 9 to 2,6-dibromo-1,4-benzoquinone 10 followed by benzylation failed to afford the desired bromonaphthoquinone 6d yet methylation did afford naphthoquinone 6b. Bromonaphthoquinone 6d was finally prepared from naphthol 18, obtained from addition of diene 9 to
研究了四氧合溴萘醌6a,6b,6c,6d的合成,这是合成3C蛋白酶抑制剂thysanone的关键中间体。将1-甲氧基-1,3-双(三甲基甲硅烷氧基)-1,3-丁二烯8加到苯中的2,6-二溴-1,4-苯醌10中,得到萘醌6a的混合物,由Diels-Alder加成反应制得通过芳构化和迈克尔加成12。当使用THF作为溶剂时,迈克尔加合物12占优势,而当使用苯时,6a占优势。萘醌6a进行苄基化萘醌6c。将1,1-二甲氧基-3-三甲基甲硅烷氧基-1,3-丁二烯9添加到2,6-二溴-1,4-苯醌10中,随后苄基化不能得到所需的溴萘醌6d,而甲基化确实得到了萘醌6b。最终由萘酚18制备溴萘醌6d,萘酚18是通过将二烯9加到1,4-苯醌17中,然后邻溴化和氧化而获得的。尝试将溴萘醌6d进行樱井烯丙基化反应可得到萘二氢呋喃21。对于2-碳甲氧基-1,4-萘醌22也观察到了类似的观察结果,该化合物也经历了樱井