ON STEROIDS .388. SYNTHESIS OF )-3-BETA,7-BETA-DIHYDROXY-17-OXOANDROST-5-EN-19-AL 19-(O-CARBOXYMETHYL)OXIME, NEW HAPTEN FOR 7-BETA-HYDROXY-DEHYDROEPIANDROSTERONE (3-BETA,7-BETA-DIHYDROXYANDROST-5-EN-17-ONE)
V. Pouzar et al., ON STEROIDS .388. SYNTHESIS OF )-3-BETA,7-BETA-DIHYDROXY-17-OXOANDROST-5-EN-19-AL 19-(O-CARBOXYMETHYL)OXIME, NEW HAPTEN FOR 7-BETA-HYDROXY-DEHYDROEPIANDROSTERONE (3-BETA,7-BETA-DIHYDROXYANDROST-5-EN-17-ONE), Collection of Czechoslovak Chemical Communications, 62(1), 1997, pp. 109-123
(19E)-3 beta,7 beta-Dihydroxy-17-oxoandrost-5-en-19-al 19-(O-carboxyme
thyl)oxime (26) was prepared in 15 steps from 17-oxoandrost-5-en-3 bet
a-yl benzoate (2, DHEA benzoate). Protection of position 17 by a boroh
ydride reduction and acetylation, subsequent functionalization of posi
tion 19 by hypoiodite reaction, oxidation to 19-aldehyde and oximation
gave successively (19E)-19-oxoandrost-5-ene-3 beta,17 beta-diyl 17-ac
etate 3-benzoate 19-(O-carboxymethyl)oxime methyl ester (10). Then 7-k
eto group was introduced by allylic oxidation with chromium(VI) oxide-
3,5-dimethylpyrazole complex and stereoselectively reduced by borohydr
ide in the presence of cerium(III) ions into 7 beta-hydroxy group. Aft
er protection as 7-isobutyrate the acetate at position 17 was removed
and oxidation recovered 17-ketone. Final deprotection revealed both hy
droxyl and carboxyl groups, giving desired 19-CMO 7 beta-hydroxy DHEA
designed as hapten for immunassays.