Photohydration of testosterone and 4-androstene-3,17-dione in aqueous solution.

Irradiation of testosterone, 4-androstene-3,17-dione, or their "half-molecule" 4,4a,5,6,7,8-hexahydro-4a-methyl-2(3H)-naphthalenone in dilute aqueous solutions with ultraviolet light of 254 nm wavelength caused rapid addition of water across the olefinic bond with formation of 5,17 beta-dihydroxy-5 alpha-androstan-3-one, 5-hydroxy-5 alpha-androstane-3-17-dione, and 9-hydroxy-10-methyl-2-decalone, respectively. Time-lapse spectrometry in the ultraviolet region showed that the photohydration of the androgenic steroids was extremely efficient and virtually free of the side reactions. Preparative photolytic reactions carried out in water-methanol solutions allowed isolation and characterization of photoproducts.