名称:
Synthesis of enantiomeric (+)- and (-)-6-(1-methylethylidene)-3,3a,6,6a-tetrahydro-2H-cyclopenta[b]furan-1-ones
摘要:
Baeyer-Villiger oxidation of racemic [2 +2 ]-cycloadduct derived from dichloroketene and dimethylfulvene gave 3,3-dichloro-6-(1-methylidene)-3,3a,6,6a-tetrahydro-2H-cyclopenta[b]furan-2-one, and opening of the lactone ring in the latter with (+)-alpha-methylbenzylamine produced diastereoisomeric amides which can be readily separated by chromatography on silica gel. The subsequent lactonization and reductive dechlorination afforded enantiomeric (-)- and (+)-6-(propan-2-ylidene)-3,3a,6,6a-tetrahydro-2H-cyclopenta[b]-furan-1-ones.