Medium-ring 1,5-dienes. Part III. Cyclisation of germacra-1(10),4,7-(11)-triene oxides

Abstract

The mono-oxides of germacra-1(10),4,7(11)-triene (1) have been prepared and an explanation is offered for the relative proportions obtained. Cyclisation of the 1,10-oxide yields selinane derivatives, whereas guaianes are obtained from the 4,5-oxide. Reductive cyclisation of the latter gives a guaiane, and on pyrolysis it is converted into a bicyclo[4.1.0]heptane derivative having the carbon skeleton found in the carabrone group of sesquiterpenes.