Conversion of dehydro abietic acid into a steroid skeleton formation of the a ring part 2
Tahara, A.; Harigaya, Y.; Onda, M.
Chemical and Pharmaceutical Bulletin 23(9): 1996-2000
Conversion of dehydroabietic acid to a steroid skeleton was attempted. The oxo ester methyl 13-isopropyl-4-oxo-16-nor-5x-podocarpa-8,11,13-trien-15-oate an important intermediate in the synthesis of 4, was synthesized from 7 having a double bond in the A ring. The oxo ester was confirmed as having the .alpha. configuration at the 5-position.