Synthesis of Racemic and Enantiomerically Enriched a-Oxyfunctionalized Benzocyclanones and Chromanones by Dimethyldioxirane and Dimethyldioxirane/Mn(III) salen System
Enolacetates of benzocyclanones and chromanones were synthesized and treated with dimethyldioxirane and the asymmetric oxidizing system dimethyldioxirane/chiral, non-racemic Mn(III) salen complex/axial ligand. The latter reagent resulted in the corresponding enantiomerically enriched cyclic alpha-hydroxy ketones and their acetates in moderate-to-good yields and modest enantioselectivity under mild and neutral conditions from tetralone and chromanone. On the contrary, flavanone provided poor yields due to the competitive C-H insertion at position 2. The use of R,R-Mn(III)salen catalyst induced an S absolute configuration at the position alpha in the whole series.
Novel photoreactions of chromene derivatives. The photolysis of 4-acetoxy-2-chromene.
作者:Maria J. Climent、Hermenegildo Garcia、Miguel A. Miranda、J. Primoa
DOI:10.1016/s0040-4020(01)90037-7
日期:1987.1
Donnelly, Dervilla M.X.; Finet, Jean-Pierre; Stenson, Paul H., Heterocycles, 1989, vol. 28, # 1, p. 15 - 18
作者:Donnelly, Dervilla M.X.、Finet, Jean-Pierre、Stenson, Paul H.
DOI:——
日期:——
CLIMENT M. J.; GARCIA H.; MIRANDA M. A.; PRIMO J., TETRAHEDRON, 43,(1987) N 5, 999-1002
作者:CLIMENT M. J.、 GARCIA H.、 MIRANDA M. A.、 PRIMO J.