Enantioselective ring construction through asymmetric olefin-ketene cycloaddition. A highly enantiocontrolled approach to (-)-.alpha.-cuparenone and (+)-.beta.-cuparenone
Enantioselective ring construction through asymmetric olefin-ketene cycloaddition. A highly enantiocontrolled approach to (-)-.alpha.-cuparenone and (+)-.beta.-cuparenone