Intramolecular [4 + 3] cycloadditions – Stereochemical issues in the cycloaddition reactions of cyclopentenyl cations – A synthesis of (+)-dactylol
作者:Michael Harmata、Paitoon Rashatasakhon、Charles L Barnes
DOI:10.1139/v06-122
日期:2006.10.1
Five cyclopentanones were prepared for the purpose of examining the effects of stereogenic centers on the course of the intramolecular [4 + 3] cycloaddition reactions of cyclopentenyl cations. One substrate reacted with very high levels of diastereoselectivity and was converted to (+)-dactylol. The cyclopentenone without stereogenic centers on the tether or the five-membered ring gave two cycloadducts
为了检查立体中心对环戊烯基阳离子的分子内 [4 + 3] 环加成反应过程的影响,制备了五种环戊酮。一种底物以非常高的非对映选择性反应并转化为 (+)-dactylol。在系链或五元环上没有立体中心的环戊烯酮产生两个环加合物,内型异构体仅略微优于外型。其他底物反应的立体选择性通常从好到差。导致(+)-dactylol 的底物的差向异构体提供了环加合物的所有可能的异构体,具有相对较差的立体选择性。关键词:环加成,全合成,dactylol。