3-Methylcyclohex-2-enone derivatives as initiators of cyclisation. Part 2. Monocyclisations to six-membered rings

Cyclisation of 3-methylcyclohex-2-enones and the derived epoxides containing alkene, alkyne, and aryl side-chains yields bicyclo[4.4.0]decane derivatives when the alkene or alkyne is electronically biased towards six-membered ring formation and when the alkene is electronically unbiased.