Exploitation of chemical predisposition in synthesis: an approach to the manzamenones
Al-Busafi, Saleh; Doncaster, Jeremy R.; Drew, Michael G. B.; Regan, Andrew C.; Whitehead, Roger C.; Al-Busafi Saleh; Department of Chemistry, The University of Reading; Doncaster Jeremy R.; Department of Chemistry, The University of Manchester; Drew Michael G. B.; Department of Chemistry, The University of Reading; Regan Andrew C.; Department of Chemistry, The University of Manchester; Whitehead Roger C.; Department of Chemistry, The University of Manchester
Журнал:
Journal of the Chemical Society, Perkin Transactions 1
Дата:
2002
Аннотация:
Full details of the syntheses of manzamenones A, C and F are reported, using an approach modelled on a plausible biogenetic theory. The key step of the approach is a â one-potâ conversion of the antileukemic cyclopentenone, untenone A, to manzamenone A which occurs in reasonable yield and which proceeds via a reaction sequence of dehydration, Dielsâ Alder dimerisation and retro-Dieckmann reaction. The synthetic approach has also been applied to the preparation of a number of shorter alkyl chain analogues of the natural products. Using a combination of NMR and X-ray crystallographic data for the shorter alkyl chain analogues of manzamenone A, it is suggested that the relative stereostructures of the majority of the manzamenones should be revised such that the acyl group at the C2 position lies on the α-face and that at the C5 position resides on the β-face.
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