corresponding cyclopentenones has been undertaken with the aid of an alkyl substituent on the three-membered ring. These ring expansion reactions proceed with exceptional regioselectivity irrespective of the cis/trans stereochemistry of the substituents on the three-membered ring. β-Carbon elimination is the common feature in the absence of a chelating group at the 4′-position in the alkyne chain.
借助于三元环上的烷基取代基,进行了Ru(II)催化的烯丙基和炔基
环丙醇重排成相应的
环戊烯酮的比较研究。不论三元环上取代基的顺式/反式立体
化学如何,这些扩环反应都具有出色的区域选择性。在炔链的4'-位不存在螯合基团的情况下,β-碳消除是其共同特征。