Stereocontrolled Synthesis of Spiro[n.2]alkenes by Ring Contraction of Fused-Cyclobutanols
作者:Kiyosei Takasu、Yuuki Nagamoto、Yoshiji Takemoto
DOI:10.1002/chem.201000930
日期:——
An unusual ring‐contraction rearrangement to give spirocyclopropanes from fused cyclobutanols (see scheme) has been developed. It is found that the strain energy of the substrates derived from an additional fused ring and the stereoelectronic effect of the migrating σ bond are important factors. It is noteworthy that the rearrangement proceeds in a stereospecific manner. Moreover, the method provides