FIELD: organic synthesis. SUBSTANCE: invention provides method of preparing 16beta-methyl steroid with formula I: 16β (I), which is distinguished by that compound of general formula II: 
(II), wherein cycles A and B form residue substituted by keto group in position 3 as in formula 
optionally protected by cyclic acetal- or thioacetal-type groups depicted by formulas 
, 
or 
with n=2 or 3, is treated with dehydration agent to give compound III: 
(III). The latter (preliminarily protected in case it bears free keto group) is affected by an organometallic methylation agent to give, after hydrolysis of intermediate imine, methyl ketone of formula IV: 
(IV), which is further treated with epoxidation agent in alkali medium to give compound of formula V: 
(V). 20-Keto group in compound V is then protected by a cyclic acetal-type group as above to form protected compound VI: 
(VI), which is treated with an organometallic methylation agent to give 16 beta-methyl derivative depicted by general formula VII: 
(VII). The latter is finally deprotected in position 3 and 20 to form desired compound I. EFFECT: simplified synthetic procedure. 8 cl
