Jump to main content
Jump to site search

Issue 6, 1993
Previous Article Next Article

Synthesis of (±)-thaps-7(15)-ene and (±)-thaps-6-enes


The synthesis of (±)-3a,4,4,7a-tetramethylhydrindan-2-one 8, containing three contiguous quaternary carbons as present in thapsanes, and the total synthesis of thaps-7(15)-ene 6 and thaps-6-ene 7, probable biogenetic precursors of thapsanes, have been achieved. Thus, orthoester Claisen rearrangement of cyclogeraniol 14, followed by hydrolysis of the resultant ester 16 furnished the eneacid 13. Copper sulfate-catalysed intramolecular cyclopropanation of the diazo ketone 18, derived from the acid 13, generated the cyclopropyl ketone 12. Regiospecific reductive cleavage of cyclopropyl ketone 12 furnished the hydrindanone 8, whereas the diazo ketone 26 furnished the hydrindanone 28avia the cyclopropyl ketone 27. Wittig methylenation of the hydrindanone 28a furnished thaps-7(15)-ene 6, which on isomerisation gave thaps-6-ene 7. Allylic oxidation of thaps-6-ene furnished the thapsenone 31, a degradation product of the natural thapsane 1b.

Back to tab navigation

Article type: Paper
DOI: 10.1039/P19930000667
J. Chem. Soc., Perkin Trans. 1, 1993, 667-673

  •   Request permissions

    Synthesis of (±)-thaps-7(15)-ene and (±)-thaps-6-enes

    A. Srikrishna and K. Krishnan, J. Chem. Soc., Perkin Trans. 1, 1993, 667
    DOI: 10.1039/P19930000667

Search articles by author