Patent ID: 7038040

Claim:
A process for the formation of a compound of Formula I: wherein -A-A- represents the group —CHR 4 —CHR 5 — or —CR 4 ═CR 5 —; -B-B- represents the group —CHR 6 —CHR 7 — or an alpha- or beta-oriented group of Formula III: R 1 represents an α-oriented lower alkoxycarbonyl or hydroxycarbonyl radical; R 3 , R 4 and R 5 are independently selected from the group consisting of hydrogen, halo, hydroxy, lower alkyl, lower alkoxy, hydroxyalkyl, alkoxyalkyl, hydroxy carbonyl, cyano, and aryloxy; R 6 and R 7 are independently selected from the group consisting of hydrogen, halo, lower alkoxy, acyl, hydroxyalkyl, alkoxyalkyl, hydroxycarbonyl, alkyl, alkoxycarbonyl, acyloxyalkyl, cyano, and aryloxy; and R 8 and R 9 are independently selected from the group consisting of hydrogen, hydroxy, halo, lower alkoxy, acyl, hydroxyalkyl, alkoxyalkyl, hydroxycarbonylalkyl, alkoxycarbonylalkyl, acyloxyalkyl, cyano, and aryloxy, or R 8 and R 9 together comprise a carboxylic or heterocyclic ring structure, or R 8 or R 9 together with R 6 or R 7 comprise a carbocyclic or heterocyclic ring structure fused to the pentacyclic D ring; the process comprising epoxidizing a compound of Formula II, said compound of Formula II having the structure: wherein -A-A-, -B-B-, R 1 , R 3 , R 8 and R 9 are as defined above; wherein preparation of said compound of Formula II comprises eliminating a leaving group from a compound of Formula IV, said compound of Formula IV having the structure: wherein -A-A-, -B-B-, R 1 , R 3 , R 8 and R 9 are as defined above, and R 2 is a leaving group the abstraction of which is effective for generating a double bond between the 9- and 11-carbon atoms.