P16CM is synthesized from prednisolone (I) via the key 16,17-dehydro intermediate (III). The compound (III) is prepared by literature procedures from prednisolone by its conversion to prednisolone 17,21-diacetate (II), followed by a potassium acetate-induced acyloxy elimination reaction. Michael addition to (III) with KCN provides the 21-acetoxy-16alpha-cyano compound, which is deprotected at C-21 and reprotected with a base-stable tetrahydropyranyl (THP) group to provide (IV). A base hydrolysis of (IV), followed by deprotection at C-21 and esterification at the 16-carboxylate, gives (V), the 17-desoxy analogue of P16CM. 17alpha-Hydroxylation of (V) via the intermediate 17,20-enol acetate, using dilute peroxyacetic acid solution at low temperature, yields P16CM.

P16CM is synthesized from prednisolone (I) via the key 16,17-dehydro intermediate (III). The compound (III) is prepared by literature procedures from prednisolone by its conversion to prednisolone 17,21-diacetate (II), followed by a potassium acetate-induced acyloxy elimination reaction. Michael addition to (III) with KCN provides the 21-acetoxy-16alpha-cyano compound, which is deprotected at C-21 and reprotected with a base-stable tetrahydropyranyl (THP) group to provide (IV). A base hydrolysis of (IV), followed by deprotection at C-21 and esterification at the 16-carboxylate, gives (V), the 17-desoxy analogue of P16CM. 17alpha-Hydroxylation of (V) via the intermediate 17,20-enol acetate, using dilute peroxyacetic acid solution at low temperature, yields P16CM.

P16CM is synthesized from prednisolone (I) via the key 16,17-dehydro intermediate (III). The compound (III) is prepared by literature procedures from prednisolone by its conversion to prednisolone 17,21-diacetate (II), followed by a potassium acetate-induced acyloxy elimination reaction. Michael addition to (III) with KCN provides the 21-acetoxy-16alpha-cyano compound, which is deprotected at C-21 and reprotected with a base-stable tetrahydropyranyl (THP) group to provide (IV). A base hydrolysis of (IV), followed by deprotection at C-21 and esterification at the 16-carboxylate, gives (V), the 17-desoxy analogue of P16CM. 17alpha-Hydroxylation of (V) via the intermediate 17,20-enol acetate, using dilute peroxyacetic acid solution at low temperature, yields P16CM.

P16CM is synthesized from prednisolone (I) via the key 16,17-dehydro intermediate (III). The compound (III) is prepared by literature procedures from prednisolone by its conversion to prednisolone 17,21-diacetate (II), followed by a potassium acetate-induced acyloxy elimination reaction. Michael addition to (III) with KCN provides the 21-acetoxy-16alpha-cyano compound, which is deprotected at C-21 and reprotected with a base-stable tetrahydropyranyl (THP) group to provide (IV). A base hydrolysis of (IV), followed by deprotection at C-21 and esterification at the 16-carboxylate, gives (V), the 17-desoxy analogue of P16CM. 17alpha-Hydroxylation of (V) via the intermediate 17,20-enol acetate, using dilute peroxyacetic acid solution at low temperature, yields P16CM.