A short and convergent synthesis of the phytoalexins vignafuran, 6-demethylvignafuran, and moracin M via directed lithiation reaction.
作者:Mitsuaki WATANABE、Kenji KAWANISHI、Sunao FURUKAWA
DOI:10.1248/cpb.39.579
日期:——
2-Methyl-5-(tert-butyldimethylsilyloxy)phenyl N, N, N', N'-tetramethylphosphorodiamidate was lithiated with sec-BuLi in the presence of N, N, N', N'-tetramethylethylenediamine at -105°C to generate the corresponding benzylic anion. This benzylic anion was reacted with various methyl benzoates to provide deoxybenzoin derivatives which, without purification, were treated with formic acid to give 2-aryl-6-hydroxybenzo[b]furans. The utility of this strategy has been demonstrated by its application to the short synthesis of phytoalexins, such as vignafuran, 6-demethylvignafuran, and moracin M.
2-甲基-5-(叔丁基二甲基硅氧基)苯基 N, N, N', N'-四甲基磷酸二胺盐与 sec-BuLi 在 N, N, N', N'-四甲基乙烯二胺的存在下,在 -105°C 下进行锂化,生成相应的苄阴离子。该苄阴离子与各种甲基苯甲酸酯反应,生成去氧苯醌衍生物,这些衍生物在未进行纯化的情况下与甲酸处理,得到 2-芳基-6-羟基苯并[b]呋喃。该策略的实用性已通过其在短时间合成植物抗生素中的应用得以验证,如 viganfuran、6-去甲基 viganfuran 和 moracin M。