SYNTHESIS OF (15E)-17-BETA-HYDROXYANDROST-4-ENE-3,15-DIONE 15-(O-CARBOXYMETHYL)OXIME, A POTENTIAL HAPTEN FOR TESTOSTERONE IMMUNOASSAYS

The kev intermediate, 15-oxandrost-5-ene-3 beta, 17 beta-diyl 3-acetat e 17-benzoate (10), was prepared by a five-step procedure based on the addition of 4-methoxybenzyl alcohol to 3 beta-hydroxyandrosta-5,15-di en-17-one (1). The resulting C-15 isomers were separated as acetates. In both series, the 17-ketones were reduced to 17 beta-hydroxy derivat ives and after benzoylation, the protecting methoxyphenylmethyl group at position 15 was removed with 2,3-dichloro-5,6-dicyano-1,4-benzoquin one, leaving 15 beta-hydroxyandrost-5-ene-3 beta,17 beta-diyl 3-acetat e 17-benzoate (6) and its 15 alpha-isomer 9, After Jones oxidation, bo th benzoates afforded the identical ketone 10. The reaction of 10 with (O-carboxymethyl)hydroxylamine in pyridine followed by diazomethane e sterification gave (15E)-15-oxandrost-5-ene-3 beta,17 beta-diyl 3-acet ate 17-benzoate 15-(O-carboxymethyl)oxine methyl ester (11). Methyl es ter 11 was successively submitted to acidic deacetylation, Oppenauer o xidation, potassium hydroxide treatment, and reesterification with dia zomethane to give (15E)-17 beta-hydroxyandrost-4-ene-3,15-dione 15-(O- carboxymethyl)oxime methyl ester (14). After purification, ester 14 wa s hydrolyzed with potassium hydrogen carbonate in aqueous methanol at elevated temperature into free testosterone 15-(O-carboxymethyl)oxime (15). (C) 1996 by Elsevier Science Inc.