4087-12-1Relevant articles and documents
Steroidal N-Nitroamines. Part 1. Denitroamination of Steroidal 4β-,6β-,7α-, and 7β-Nitroamines
Francisco, Cosme G.,Melian, Daniel,Salazar, Jose A.,Suarez, Ernesto
, p. 923 - 930 (2007/10/02)
The α-hydroxy-nitroamines 6β-nitroamino-5α-cholestane-3β,5α-diol (26) and 6β- and 4β-nitroamino-5α-cholestan-5α-ol (27) and (30) have been prepared by reactions of cholest-5-en-3β-yl formate, cholest-5-ene, and cholest-4-ene with nitrous acid and boron trifluoride-ether complex, and subsequent treatment with sodium borohydride.The nitroamines (12) and (25), obtained by nitrosation of the corresponding oximes, undergo similar reduction to yield 6β-nitroamino-5α-cholestan-3β-yl acetate (32) and the 7β- and 7α-nitroaminocholest-5-en-3β-yl acetates (36) and (38).The results of denitroamination reactions of these nitroamines, performed with acetic anhydride and pyridine, are consistent with a mechanism involving a nitrous oxide-separated ion-pair intermediate (6).The nitroamines (26), (27), and (30) gave the corresponding 5α- and 4α-oxirans (28), (29), and (31) by intramolecular nucleophilic substitution.The nitroamine (32) yields, by a hydrogen β-elimination, the acetyl derivatives of cholest-4-en-3β-ol (33), cholest-5-en-3β-ol (34), and cholest-6-en-3β-ol (35).The acetates of cholest-5-ene-3β,7β-diol (37) and cholest-5-ene-3β,7α-diol(39) were obtained from the 7β- and 7α-nitroamines (36) and (38) through substitution by a counter-ion, a total retention of configuration for the 7α-nitroamine and 14percent inversion for the 7β-isomer being observed.
