REGIO AND STEREO SELECTIVE HYDROGENATION OF 17-SUBSTITUTED 13-BETA-ETHYL-11-BETA-HYDROXY-GONA-4,9-DIEN-3-ONES AND NMR STUDY

摘要

Selective hydrogenation of 17-Substituted 13 beta-ethyl-11 beta-hydroxy-gona-4,9-dien-3-ones (3a,b) in Pd(O)/SrCO3-pyridine media gives the corresponding 11 beta-hydroxy-gon-4-en-3-ones (4a,b). The complete assignments of H-1 and C-13 NMR spectra of the main products (4a,b) are made by one and two dimensional NMR techniques, such as J-MOD or ATP, H-1-H-1 COSY, HETCOR and COLOC, with the aid of the templates for recognition of proton signals suggested by Kirk and co-workers. The substituent effects of 10-CH3, 11 beta-OH and 18-CH3 in 4-en-3-one steroids are summarised from model compounds and the good correlation is found between experimental and calculated carbon-13 chemical shifts of 4a,b and 15. The high stereo selectivity is due to steric hindrance of substituents at beta-side. The solvent effects are also discussed [References: 34]