Synthesis of (+)-Artemeseole

The synthesis of the monoterpene (+)-artemeseole (1b) is accomplished by starting from (Z)-dienol 5. Sharpless epoxidation of 5 gives oxirane 4. Attempted opening of the epoxide ring in 4 or in derivatives 8a, b by various allyl or acetylide anions gives side reactions, but the desired coupling with a C3 unit is achieved in the reaction of silyl-protected oxirane 8b with 9 or 13 giving 17 and 19a, respectively. Alkenol 19a is further converted into oxirane 21 by desilylation, tosylation, and base-induced epoxide formation. Anion generation from 21 by reductive desulfurization yields (dialkenylcyclopropyl)methanol 3. Acid-catalyzed cyclization to a tetrahydrofuran completes the synthesis of 1b.