New Domino Reactions with Sultones

Abstract

Hydroxyl-containing α,β-unsaturated δ-sultones undergo a diastereoselective conjugate reduction by Red-Al. This transformation can be extended to a domino elimination/1,4-hydride addition of a tricyclic sultone substrate that is readily available via intramolecular Diels-Alder reaction. Bicyclic γ-keto δ-sultones are converted into diastereomerically pure oxabicyclic ketones in a domino desulfurization/oxy-Michael addition using DBU.

Key words

sultones - conjugate additions - reductions - desulfurizations - domino reactions

References and Notes

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8

MeLi is superior to BuLi for elimination of 5a to yield 6a.^³

11

The ratio of the diastereomers 7a/8a varied to some extent from run to run, while 7b was usually obtained as a single isomer.

12

CCDC 724219 contains the supplementary X-ray crystallographic data for this paper. These data can be obtained free of charge from The Cambridge Crystall-ographic Data Centre via www.ccdc.cam.ac.uk/data_request/cif.