PTCL2-CATALYZED CONVERSION OF 1,6-ENYNES AND 1,7-ENYNES TO 1-VINYLCYCLOALKENES - ANOMALOUS BOND CONNECTION IN SKELETAL REORGANIZATION OF ENYNES

The treatment of 1,6- and 1,7-enynes with a catalytic amount of PtCl2 in toluene at 80 degrees C results in sheletal reorganization (cyclore arrangement) of the enynes to give 1-vinylcycloalkenes in high yields. A deuterium labeling experiment indicates that two mechanistic paths are operating for the cyclorearrangement. The nature and position of s ubstituents affect the reaction course. Anomalous carbon-carbon bond f ormation is attained selectively in the reaction of 1,6-enynes having an, ester group at the terminal acetylenic carbon.