Clarithromycin1* (1, 6-O-methylerythromycin A, A-56268, TE-031) is a new macrolide currently undergoing clinical development. The excellent properties2) of 1 make it attractive for further synthetic modifications. It is knownthat, reduction of the 9-keto group of erythromycin A (2), for example with sodium borohydride, gives the corresponding secondary alcohol, predominantly as the 9(S) epimer,...

1. The synthesis of a number of 19-substituted androgens is described. 2. A method for the partially stereospecific introduction of a tritium label at C-19 in 19-hydroxyandrost-5-ene-3beta,17beta-diol was developed. The 19-(3)H-labelled triol produced by reduction of 19-oxoandrost-5-ene-3beta,17beta-diol with tritiated sodium borohydride is tentatively formulated as 19-hydroxy[(19-R)-19-(3)H]an...

From the time immemorial, sodium borohydride has been used for the reagent of choice for reducing various carbonyl compounds and acid chlorides in protic solvents. Over the past decades the utility of sodium borohydride has been greatly expanded and various modifications have been developed. Reductive dechlorination of aromatic halo nitro compounds have a great significance in the field of orga...