In this paper, we present an efficient procedure for the transformation of a soybean phytosterol mixture
into pregna-1,4,16-triene-3,20-dione, which is a key intermediate for the synthesis of valuable corticoids.
The possibility of using two alternative methods for 1(2)-dehydrogenation of pregna-4,16-diene-3,20-dione -
chemical and microbiological - was shown. Microbiological 3-keto-4-ene steroid 1(2)-dehydrogenation was
carried out using actinobacterial cells of Nocardioides simplex VKM Ac-2033D. The structures of the synthesized
compounds were confirmed by the IR, MS, and 1H-NMR methods.