A convenient preparation of (S)-(−)-4-hydroxy-2-methylcyclopent-2-en-1-one and its application as a chiral synthetic equivalent of 2-methylcyclopent-2-en-1-one in the terpenoid synthesis
作者:Karol Michalak、Jerzy Wicha
DOI:10.1016/j.tet.2014.06.006
日期:2014.8
from 1-(2-furyl)ethanol using modified Piancatelli rearrangement and enzymatic kinetic resolution of the racemate was developed. An application of O-protected derivatives of 4-hydroxy-2-methylcyclopent-2-en-1-one to terpenoid synthesis through tandem conjugate addition of allyl-metal reagents, enolate trapping, and consecutive Mukaiyama–Michael addition was studied. An optically active azulene derivative
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