CYCLOADDITIONS OF 1,3-OXAZOLIUM-4-OLATES (ISOMUNCHNONES) BY RHODIUM(II)-INDUCED DECOMPOSITION OF ALPHA-DIAZOCARBONYL DERIVATIVES OF (5R)-PHENYLOXAZIN-3-ONE AND (5S)-PHENYLOXAZIN-3-ONE AS A CHIRAL TEMPLATE
R. Angell et al., CYCLOADDITIONS OF 1,3-OXAZOLIUM-4-OLATES (ISOMUNCHNONES) BY RHODIUM(II)-INDUCED DECOMPOSITION OF ALPHA-DIAZOCARBONYL DERIVATIVES OF (5R)-PHENYLOXAZIN-3-ONE AND (5S)-PHENYLOXAZIN-3-ONE AS A CHIRAL TEMPLATE, Tetrahedron letters, 38(25), 1997, pp. 4517-4520
Cycloadducts (6-9) were synthesised from isomunchnone derivatives of (
5R)- and (5S)-phenyloxazin-3-one by rhodium(II)-catalysed decompositio
n of alpha-diazocompounds (3a-c). Additions to various carbon-carbon d
ipolarophiles proceeded with high endo/exo-selectivities and moderate
diastereofacial selectivities. (C) 1997 Elsevier Science Ltd.