REACTION OF (Z)-(PHENYLVINYL)ACETYLENES AND (Z)-(CYCLOPROPYLVINYL)ACETYLENES WITH FISCHER CARBENE-CHROMIUM COMPLEXES - AN ALTERNATIVE APPROACH TO BENZANNULATION AND CYCLOPENTANNULATION

The reaction of (Z)-(phenylvinyl)acetylenes and carbene complexes prov ides benzannulation products in fair to good yields. Similarly, the re action of (Z)-(cyclopropylvinyl)acetylenes and carbene complexes provi des cyclopentenone derivatives. When the carbene complex is capable of further ring-forming reactions, subsequent ring-forming steps occur p referentially from the substituent on the enyne.