Volkmann RA,
Andrews GC,
Johnson WS.
Stanford University, USA
Novel Synthesis of Longifolene.
J. Am. Chem. Soc. 1975;
97: 4777-4779
DOI:
10.1021/ja00849a062
Key words
(±)-longifolene - (±)-longicamphenylone - sesquiterpene - formal [3+2] cycloaddition
Significance
In 1954, Johnson and co-workers presented a total synthesis of the tricyclic sesquiterpene
(±)-longifolene featuring an elegant formal [3+2] cycloaddition that provided fast
access to the natural product.
Comment
Enyne G was accessed in four steps from enone A with an overall yield of 59%. Key cycloaddition of G efficiently provided the carbon skeleton of the natural product in 75% yield. Further
elaboration of this intermediate afforded (±)-longifolene in four steps.
