| Abstract
| - Treatment of the 7-O-acetyl derivative (2)of eriocephalin (1) with HCl yielded minorquantitiesof the 4,5-seco-neoclerod-5(19)-ene derivatives 3and 4. Under the same treatment, capitatin(6) underwent an identical fragmentation reaction giving9 in good yield, via the unstablechlorohydrin intermediate 8. Sodium cyanoborohydridereduction of 9 yielded compounds 10and 11 by a stereoselective 1,4-reduction process. Themechanistic aspects of these transformations are discussed. The 4,5-seco derivatives 9,10, and 11 can be useful intermediates forthesynthesis of natural and synthetic neoclerodane diterpenoids, which areof interest on accountof their activity as insect antifeedants and other important biologicalproperties.
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