synthesis of 6-hydroxy-7-(hydroxymethyl)-4-methylenehexahydrocyclopenta[c]pyran-1(3H)-one has been accomplished. A key feature of the synthesis includes facile construction of the bicyclic lactone intermediate via intramolecular Pd(0)-catalyzed allylic alkylation and the efficient transformation of this intermediate into the iridoid skeleton employing silicon tethered radical cyclization.
已经完成了6-羟基-7-(羟甲基)-4-亚甲基六氢环戊[ c ]吡喃-1(3 H)-one的第一次全合成。合成的关键特征包括通过分子内Pd(0)催化的烯丙基烷基化轻松构建双环内酯中间体,以及利用硅系自由基环化将该中间体有效转化为虹彩骨架。
Diastereoselective Iodocarbocyclization Reaction of 2- or 3-Oxy-4-pentenylmalonate Derivatives
induction in the iodocarbocyclizationreaction of 4-pentenylmalonate derivatives having a stereogenic center at an allylic or a homoallylic position has been investigated. The iodocarbocyclizationreactions of 3-oxy-4-pentenylmalonate derivatives proceeded with high cis-selectivity through stereoelectronic control of the oxygenated substituent at an allylic position. In the reaction of (S)-2-siloxy-4-pentenylmalonate