Wiley, European Journal of Organic Chemistry, 19(2001), p. 3731, 2001
DOI: 10.1002/1099-0690(200110)2001:19<3731::aid-ejoc3731>3.0.co;2-2
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To examine the reactivity of conjugated diene steroids towards methyltrioxorhenium (MTO)-catalysed oxidation with the urea−hydrogen peroxide adduct (UHP) and its possible use in functionalization of the rings of the steroid nucleus, the reactions of the MTO/UHP system with cholesta-3,5-diene (4) and 5α-cholesta-7,9(11)-dien-3β-yl acetate (13) in aprotic solvents were investigated. These oxidations were performed both at 0 °C and at 25 °C, in either CHCl3 or diethyl ether as solvents, and in the presence of pyridine as ligand. Three new 4,5-epoxy-3,6-dihydroxyl compounds 10, 11, and 12 were isolated from the treatment of diene 4 in CHCl3 at 0 °C, while oxidations of the Δ7,9(11)-diene steroid 13 allowed us to isolate the new monoepoxy and diepoxy steroids 14 and 15 and the new triol 19. The structures of all new steroids were verified on the basis of chemical evidence and interpretation of spectroscopic data including H-H COSY, HMBC, and HMQC experiments.