Substituent Effects on the Cyclization Mode of 7‐Sulfonyl‐3‐hepten‐1,5‐diynes and 11‐Sulfonylundeca‐3,7‐dien‐1,5,9‐triynes.

Abstract

Ring closure reactions Ring closure reactions O 0130Substituent Effects on the Cyclization Mode of 7-Sulfonyl-3-hepten-1,5-diynes and 11-Sulfonylundeca-3,7-dien-1,5,9-triynes. -It is found that the substituent on the alkyne terminus in 7-sulfonyl-3-hepten-1,5-diynes has no influence on the cyclization mode. However, substituents on the alkene terminus play an important role. In the presence of hydrogen substituents, Myers-type cyclization takes place, while starting from benzene analogues like (VII), considerable amounts of Schmittel-type cyclization products are obtained. The cyclization mode of 11-sulfonylundeca-3,7-dien-1,5,9-triynes, however, is strongly dependent on substituents on the alkyne terminus.