Cyclization of 1,5-hexadien-3-ols. Obtention of chloro-octalines, octalones and hexahydro-azulenones from allyl-pulegols

The TiCl4 mediated cyclization of allyl-pulegols gives chlorooctalines (1,5-hexadien-3-ol system is cyclized into 4-chlorocyclohexene moiety). From chloro-octalines, octalones and hexahydro-azulenones are obtained respectively into three and two steps.