570-88-7Relevant articles and documents
Oxymercuration-demercuration of steroidal olefins: Extension and reinvestigation
Ahmad, M. S.,Ayad, Tariq M.
, p. 763 - 768 (2007/10/02)
Cholesterol (I) on mercuration-demercuration gives 3β-acetoxycholest-5-ene (II), 3β,6β-dihydroxy-5α-cholestane (V), 6β-acetoxy-3β-hydroxycholest-4-ene (VI), 3β,6β-dihydroxycholest-4-ene (VII) and its diacetate (VIII).Under similar reaction conditions, II affords I, VIII, 3β6β-diacetoxy-5α-cholestane (X) and 5ξ-acetoxycholestan-3-one (XI).On demercuration with NaBH4 - NaOH, the adduct from I gives II, V, VII and cholest-4-en-3-one (IX).Under similar conditions, the adduct from II affords I, V, VII and XI.OM - DM of cholest-5-ene (III) and 3β-chlorocholest-5-ene (IV) has been reinvestigated in order to suport our earlier observation in the sense that 3-substituted products are obtained from III.Cholest-5-ene (III) on OM - DM gives I and II, in addition to the products reported earlier.On demercuration with NaBH4-ethylene glycol the adduct from III gives additional products, such as 4β-acetoxycholest-5-en-7-one (XII) and 7-acetoxy-3β-hydroxycholest-4-en-6-one (XIII).The chloroolefin (IV) on OM - DM gives an additional product, 3β-chloro-6β-hydroxy-5α-cholestane (XIV).Interestingly the mercury adduct from IV on demercuration with NaBH4-ethylene glycol affords an additional product, 3β-(2-acetoxyethoxy)cholest-5-ene (XV).The structures of the compounds have been established by elemental analyses, spectral data, chemical transformation and comparison with authentic samples.Mechanisms for the formation of V and VIII from I and that of II and XII from III have been proposed.
