Open AccessIntramolecular Oxonium Ylide Formation–[2,3] Sigmatropic Rearrangement of Diazocarbonyl-Substituted Cyclic Unsaturated Acetals: A Formal Synthesis of Hyperolactone C
Author(s) -
David M. Hodgson,
Stanislav Man,
Kimberley Jade Powell,
Ziga Perko,
Minxiang Zeng,
Elena MorenoClavijo,
Amber L. Thompson,
Michael D. Moore
Publication year - 2014
Publication title -
journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.2
H-Index - 228
eISSN - 1520-6904
pISSN - 0022-3263
DOI - 10.1021/jo501893r
Subject(s) - oxonium ion , ylide , chemistry , sigmatropic reaction , acetal , stereocenter , intramolecular force , stereochemistry , diazo , intramolecular reaction , medicinal chemistry , enantioselective synthesis , catalysis , organic chemistry , ion
Rh(II)-catalyzed oxonium ylide formation-[2,3] sigmatropic rearrangement of α-diazo-β-ketoesters possessing γ-cyclic unsaturated acetal substitution, followed by acid-catalyzed elimination-lactonization, provides a concise approach to 1,7-dioxaspiro[4.4]non-2-ene-4,6-diones. The process creates adjacent quaternary stereocenters with full control of the relative stereochemistry. An unsymmetrical monomethylated cyclic unsaturated acetal leads to hyperolactone C, where ylide formation-rearrangement proceeds with high selectivity between subtly nonequivalent acetal oxygen atoms.