描述了合成 phomactin 天然产物的对映选择性策略。使用路易斯酸引发嵌入 12 元大环的 β-碘联烯醇环化,以良好的收率和高非对映选择性获得高度官能化的双环[9.3.1]十五烷。这种碘烯酮含有天然产物 phomactin 家族 AD 环系统的取代基,适合进一步功能化。从 AD 碘烯酮中间体合成了 phomactin A 的 oxadecalin 核心。在这种不寻常的策略中,环 A 和环 B 均在大环前体内形成。
Enantioselective Synthesis of the ABC-Tricyclic Core of Phomactin A by a γ-Hydroxylation Strategy
摘要:
An enantioselective synthesis of the ABC-tricyclic furanochroman core of phomactin A has been accomplished by a gamma-hydroxylation approach. The C ring was established by gamma-hydroxylation of an a-enone. The regioselectivity was optimized by using a strong base with an oxophilic cation (t-BuLi) and a bulky oxygen donor (Davis reagent), which afforded the gamma-hydroxylation product selectively in 63% yield.