Abstract An efficient synthesis of all-(E) vitamin A acetate from 2, 2, 6-trimethyl- cyclohexanone has been achieved via the intermediacy of 1-(9-acetoxy-3, 7-dimethyl-nona- 3, 5, 7-trien-1-ynyl)-2, 2, 6-trimethyl-cyclohexanol (25), readily prepared in high yield by allylic rearrangement of tertiary propenols with glacial acetic acid. The key step in the synthesis is the transformation of 25 to the unsaturated ketone 27 (9-acetoxy-3, 7-dimethyl ...
