1,2,3,5,5,6-hexamethyl-7-oxabicyclo[4.1.0]hept-2-en-4-one

3β,4β:5α,6α-diepoxy-2,2,3α,4α,5β,6β-hexamethylcyclohexanone

1,2,2,5,6,7-Hexamethyl-4,8-dioxa-bicyclo[5.1.0]oct-5-en-3-one