- Stereoselectivity in the epoxidation and cis-hydroxylation of 16-methylene-estra-1,3,5(10)-trienes
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Epoxidation of 3-methoxy-16-methylene-estra-1,3,5(10)-trien-17-one in the presence of alkaline hydrogen peroxide gives rise to (16R)- and (16S)-spiro in similar proportions.Epoxidation of the corresponding 16-methylene 17β-alcohol and 16-methylene-17β-acetate with m-chloroperbenzoic acid does not display any significant directing effects associated with allylic functionality, whereas Sharpless epoxidation of the 16-methylene 17β-alcohol is highly stereoselective, leading exclusively to the (16R) isomer. cis-Hydroxylation of the 16-methylene 17-ketone with osmium tetroxide/4-methylmorpholine-4-oxide proceeds stereoselectively to give mainly 16α-hydroxy-16β-hydroxymethyl-3-methoxyestra-1,3,5(10)-trien-17-one.The isomeric addition products derived from these reactions are correlated by appropriate interconversions, and the assignments are corroborated by comparative reactivity of derived products. - Keywords: estra-1,3,5(10)-trienes; 16-methylene-estra-1,3,5(10)-trienes; epoxidation; Sharpless epoxidation; hydroxylation
- Bull, James R.,Kaiser, Delene A.
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- Steroid hormone-antitumor derivatives
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A process for producing a steroid hormone-antitumor derivative which selectively affects to tumor or cancer cells comprises reacting X group of a steroid hormone derivative having the formula STR1 wherein ST represents a steroid moiety having a cyclophenanthrene hydrocarbon skeleton of gonane, estrane or androstane which is bound to carboxyl group by esterifying OH group on D ring with carboxyl group; and R'' represents a C 1 -C 4 alkylene group and X represents a halogen atom, amino group, hydroxyl group, carboxyl group or a salt thereof, with a modified or non-modified reactive group of an antitumor drug to form a binded group of --O--, --COO--, --CONH--, --NH-- or STR2
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