Patent ID: 8258319

Claim:
A process for preparing Compound 17: said process comprising the steps of: (a) cyclizing Compound 18 in a first solvent at an elevated temperature wherein R 7 is selected from the group consisting of H, alkyl, alkenyl, alkynyl, alkoxy, cycloalkyl, aryl, alkylaryl, arylalkyl, and heteroaryl groups to produce a first mixture comprising α and β of the exo isomers of Compound 17A: and α and β of the endo isomers of Compound 17B: said isomers of Compound 17A having a trans-[5,6]-ring-junction; (b) epimerizing said trans-[5,6]-ring-junction of Compound 17A by treating said first mixture with a first base to produce a second mixture comprising cis-[5,6]-ring-junction-nitro-α isomer and cis-[5,6]-ring-junction-nitro β isomer of each Compound 17C and Compound 17B: and (c) treating said second mixture with a second solvent, causing said α-isomer of Compound 17C to precipitate to produce Compound 17.