A New Cyclopentannulation Approach to Bicyclo[3.3.0]octenes Employing a Tandem Michael Addition-[3 + 2]-Anionic Cyclization Sequence
摘要:
Treatment of 1-substituted dimethyl 1-pentenedioates with base in the presence of 2,3-bis(phenylsulfonyl)-1,3-butadiene results in the formation of bicyclo[3.3.0]octenes. The overall reaction involves a series of three sequential conjugate additions followed by phenyl sulfinate ion ejection.