Stereoselective reduction of C-2 substituted steroid C-3 ketones with lithium tris-(R,S-1,2-dimethylpropyl)-borohydride and sodium borohydride

Add time:08/27/2019    Source:sciencedirect.com

The effect of C-2 substitution on the stereoselective reduction of steroid C-3 ketones with lithium tris-(R,S-1,2-dimethylpropyl)-borohydride and sodium borohydride was investigated. The C-2 mono- and di-substituted chloro and methyl derivatives were predominantly reduced to one of the epimeric alcohols. The 2α-chloro and 2α-methyl derivatives of 17β-acetoxy-5α-androstan-3-one undergo stereoselective reduction with lithium tris-(R,S-1,2-dimethylpropyl)-borohydride to the axial (3α) alcohol as observed in the unsubstituted compound, whereas sodium borohydride gives predominantly the equatorial (3β) alcohol. The 2β-chloro, 2β-methyl, 2,2-dichloro, and 2,2-dimethyl derivatives are reduced predominantly to the equatorial (3β) alcohol by both reagents.

We also recommend Trading Suppliers and Manufacturers of N-(1,2-Dimethylpropyl)-2-pyridinamine (cas 111098-37-4). Pls Click Website Link as below: cas 111098-37-4 suppliers

Prev:Excess molar enthalpies of ternary mixtures of n-heptane, methyl 1,1-dimethylpropyl ether and 1,2-dimethoxyethane
Next:Volatility studies of metal chelates : VII. Gas chromatographic behaviour of chelates derived from the aromatic β-diketones 1-phenylbutane-1,3-dione and 4,4,4-trifluoro-1-(pentafluorophenyl)butane-1,3-dione☆)