Synthesis of (15 E)-17β-hydroxyandrost-4-ene-3,15-dione 15-( O-carboxymethyl)oxime, a potential hapten for testosterone immunoassays

• Published in: Steroids Vol. 61; no. 11; pp. 634 - 638
• Main Authors: Fajkos̆, Jan, C̆erný, Ivan, Pouzar, Vladimír
• Format: Journal Article
• Language: English
• Published: WOBURN Elsevier Inc 01.11.1996; Butterworth-Heinemann; Elsevier Science
• Subjects: Analytical, structural and metabolic biochemistry; Biochemistry & Molecular Biology; Biological and medical sciences; Endocrinology & Metabolism; Fundamental and applied biological sciences. Psychology; Life Sciences & Biomedicine; Other biological molecules; protecting groups; Science & Technology; synthesis; Terpenes, steroids. Hormones; testosterone 15-( O-carboxymethyl)oxime; synthesis; protecting groups; testosterone 15-( O-carboxymethyl)oxime; testosterone 15-(O-carboxymethyl)oxime; Protecting group; Testosterone; Analysis method; Androgen; Testicular hormone; Sex steroid hormone; Chemical synthesis; Hapten; Immunological method
• ISSN: 0039-128X; 1878-5867
• DOI: 10.1016/S0039-128X(96)00136-5

The key intermediate, 15-oxandrost-5-ene-3β, 17β-diyl 3-acetate 17-benzoate ( 10), was prepared by a five-step procedure based on the addition of 4-methoxybenzyl alcohol to 3β-hydroxyandrosta-5,15-dien-17-one ( 1). The resulting C-15 isomers were separated as acetates. In both series, the 17-ketones were reduced to 17β-hydroxy derivatives, and after benzoylation, the protecting methoxyphenylmethyl group at position 15 was removed with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone, leaving 15β-hydroxyandrost-5-ene-3β, 17β-diyl 3-acetate 17-benzoate ( 6) and its 15α-isomer 9. After Jones oxidation, both benzoates afforded the identical ketone 10. The reaction of 10 with ( O-carboxymethyl)hydroxylamine in pyridine followed by diazomethane esterification gave (15 E)-15-oxandrost-5-ene-3β, 17β-diyl 3-acetate 17-benzoate 15-( O-carboxymethyl)oxime methyl ester ( 11). Methyl ester 11 was successively submitted to acidic deacetylation, Oppenauer oxidation, potassium hydroxide treatment, and reesterification with diazomethane to give (15 E)-17β-hydroxyandrost-4-ene-3,15-dione 15-( O-carboxymethyl)oxime methyl ester ( 14). After purification, ester 14 was hydrolyzed with potassium hydrogen carbonate in aqueous methanol at elevated temperature into free testosterone 15-( O-carboxymethyl)oxime ( 15).