Optimization of the abnormal Beckmann rearrangement: application to steroid 17-oximes.
A novel and practical procedure was developed for the abnormal Beckmann rearrangement of steroid 17-oximes. Treatment of the 17-oximes with TFA/CH(OMe)(3) in boiling THF for 2 h gives the corresponding 13,17-seco alkene nitrile products in unprecedented high yields (70-92%). Since the alkene nitriles can be subsequently converted into 18-norsteroids, this general method provides a highly efficient route to these biologically important compounds and, by extension, to other structurally related natural products.
Wang
Cunde
C
Department of Chemistry, Nanjing University, P R China.
Jiang
Xin
X
Shi
Haijian
H
Lu
Jun
J
Hu
Yuefei
Y
Hu
Hongwen
H