It was anticipated that typeII carb

It was anticipated that type
II carbonyl ene reaction of the aldehyde 9 would generate the bicyclic
alcohol 10, which could be further elaborated into aciphyllenes.
The aldehyde 9 could be obtained from the ester 11,
which in turn could be obtained from the aldehyde 12. A two-step
(controlled ozonolysis followed by intramolecular aldol condensation)
conversion of (R)-limonene 8 into the aldehyde 12 has
already been developed by us.11a