作者:Jacek W. Morzycki、Agnieszka Z. Wilczewska、Zenon Łotowski
DOI:10.1016/0040-4039(96)00197-9
日期:1996.3
The reactions of four steroidal enamides with acetyl nitrate were studied. The nitronium ion attacks the terminal carbon atom of the enamide moiety. Further transformations of the unsaturated nitro derivative consist of an allylic oxidation or a Nef-type reaction.
Reactions of 4-azacholest-5-en-3-one, 6-azacholest-4-en-7-one, and their N-methyl derivatives with electrophilic reagents
作者:Jacek W. Morzycki、Agnieszka Z. Wilczewska
DOI:10.1016/0040-4020(96)00847-2
日期:1996.10
The reactions of four steroidal ene-lactams with electrophilic reagents, such as bromine, acetyl nitrate or CrO3, were studied. The initial electrophilic attack took place on the terminal carbon atom of the enamide system. In some cases further reactions at the allylic position were observed. There were no reactions at the nitrogen atom or in the α position to the lactam carbonyl group.
Stereocomplementary reductions of ring fused enelactams
作者:Ross A. Miller、Guy R. Humphrey、Andrew S. Thompson
DOI:10.1016/0040-4039(95)01664-4
日期:1995.10
Selective reductions of ringfusedenelactams to trans- and cis-ring fused lactams is described.
环稠合到enelactams的选择性还原反式-和顺式-环稠合的内酰胺进行说明。
A microwave promoted and Lewis acid catalysed solventless approach to 4-azasteroids
作者:Moyurima Borthakur、Romesh C. Boruah
DOI:10.1016/j.steroids.2008.01.022
日期:2008.7
The preparation of 3-oxo-4-azasteroid from A-nor-3,5-secosteroid-3-oic acid is described in a solventless condition catalysed by Lewis acid under microwave irradiation. We utilized urea as an environmentally benign source for the generation of ammonia for the aza cyclization reaction. (C) 2008 Elsevier Inc. All rights reserved.
N-Chloroazasteroids. A novel class of reactive steroid analogs. Preparation, reaction with thiols, and photochemical conversion to electrophilic N-acyl imines