Verfahren zur Herstellung von 7a-Alkylthio-steroiden

The invention comprises steroids of the general formula: wherein R1 represents hydrogen or acyl, R2 represents hydrogen or methyl, R3 represents C1 to C5 alkyl, X represents H,H; H,b -OH or =O, Y represents hydrogen or fluorine, Z represents H,H or =CH2, and R2, X, Y and Z do not simultaneously represent hydrogen, and the corresponding 1,2-dehydro compounds, and the preparation thereof by reacting steroids of the general formula: wherein R1, R2, X, Y and Z have the above significance, with the required alkyl mercaptan, optionally dehydrogenating the product either chemically or microbiologically to form the 1,2-dehydro-steroids and, if desired, saponifying the 17-ester group or esterifying the 17-hydroxy group in the D 4- or D 1,4-product obtained. Suitable chemical dehydrogenating reagents are selenium dioxide and 2,3-dichloro-5,6-dicyanobenzoquinone, and suitable dehydrogenating micro-organisms are Bacillus sphaericus var. fusiformis, Corynebacterium simplex and Fusarium solani. The esterification may be carried out with carboxylic acids including halo-, amino-and alkylamino-substituted carboxylic acids and dicarboxylic acids, and with phosphoric and sulphuric acids.