Kabat, Marek M.; Kurek, Alicja; Masnyk, Marek, Journal of Chemical Research, Miniprint, 1987, # 7, p. 1711 - 1727
作者:Kabat, Marek M.、Kurek, Alicja、Masnyk, Marek、Repke, Kurt R. H.、Schoenfeld, Werner、et al.
DOI:——
日期:——
Oxidative Fragmentation of Pregna-14,16-dien-20-ones to 14β-Hydroxyandrost-15-en-17-ones
作者:Jennifer D. Fell、Clayton H. Heathcock
DOI:10.1021/jo011175+
日期:2002.7.1
Two methods have been developed for efficient conversion of pregna-14,16-dien-20-ones into 14beta-hydroxyandrost-15-en-17-ones. One procedure consists of treatment of the ring-D dienone successively with sodium borohydride and singlet oxygen. The reaction is illustrated by the conversion of pregna-14,16-dien-20-one 1 into 14beta-hydroxyandrost-15-en-17-one 3, via the corresponding allylic alcohol 2. Although this two-step procedure is simple, it provides 3 in relatively low yield, accompanied by a smaller amount of the isomeric 14alpha-hydroxyandrost-15-en-17-one 6. An alternative one-step conversion is achieved by treatment of dienone 1 with a peroxyacid in the presence of a strong protic acid. This process is illustrated by the two-step conversion of dienone I into hydroxy ketone 11 in 51% overall yield (Scheme 5) and by the analogous conversion of dienone 13 into hydroxy ketone 24 in 61% overall yield (Scheme 11).