52. The Total Synthesis of (±)-Isocomene by an Intramolecular Ene Reaction. Preliminary communication
    Oppolzer, W.; Bättig, K.; Hudlicky, T.
    Helv. Chim. Acta 1979, 62, 1493-1496

The racemic sesquiterpene isocomene (1) has been synthesized starting from 1,7-octadien-3-one (2) in a stereoselective manner (Scheme 2). In the key step 4 → 5 the C(7), C(8)-bond was formed by an intramolecular thermal ene reaction. Further elaboration of 5 involved the ring contraction 6 → 7, the elimination 8 → 9 and the final olefin isomerization 9 → 1.

DOI : 10.1002/hlca.19790620514