title: Synthesis, Structure, and Unusual Reactivity of a Stable 3-(Oxazolidin-2-ylidene)thiophen-2-one.
abstract: Treatment of 2- and 3-thienyloxazolines with butyllithium and bis(trimethylsilyl) peroxide results in ring hydroxylation to give products that exist mainly as the oxazolidinylidenethiophenones. The 3-oxazolidinylidenethiophen-2-one is a rare example of a stable heterocyclic o-quinone methide analogue that shows a varied pattern of reactivity, including both C- and O-alkylation, Michael addition via C-5 to an acetylenic ester, tetrachlorobenzannulation across positions 4 and 5, and formation of a hexacyclic fused-ring product with N-phenyltriazolinedione. Crystal structures of the products are dominated by inter- and intramolecular NH to CO hydrogen bonding.
authors.affiliation: EaStCHEM School of Chemistry, University of St Andrews , North Haugh, St Andrews, Fife KY16 9ST, U.K.
authors.forename: R Alan
authors.initials: RA
authors.lastname: Aitken
authors.affiliation: EaStCHEM School of Chemistry, University of St Andrews , North Haugh, St Andrews, Fife KY16 9ST, U.K.
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Harper
authors.affiliation: EaStCHEM School of Chemistry, University of St Andrews , North Haugh, St Andrews, Fife KY16 9ST, U.K.
authors.forename: Alexandra M Z
authors.initials: AM
authors.lastname: Slawin