Syntheses, Reactions and Transformations of Steroidal Amines

The preparation of 12-oxygenated conanine derivatives and a partial synthesis of dihydroholarrhenine (4) have been reported. 3/3-Acetoxy-5a-pregnan-12,20-dione ethylene acetal (5 a), prepared from hecogenine acetate by published procedures, was transformed to the oxime (5b) which was reduced by sodium in propanol to the epimeric 20-amino-derivatives, with hydrolysis of the 3-acetoxy-group. Separation of the 20o -epimer (6a) was effected by crystallization and column chromatography. Reduction of the cathylate (6b) gave (6c) which was oxidized to the 

3-ketone (7). Reductive amination of (7) led to the epimeric 3-dimethylamino-compounds (8a) and (9). Hofmann-Lofler cyclization on (8b) afforded 12-oxodihydroconessine (10). Catalytic reduction of (10) over Pd/C furnished (4). Similar treatment of the 3a-dimethylamino-derivative (9) led to 3-epiholarrhenine (11). 

The Hofmann-Lofler reaction on 20j8-methylamino-5a-pregnan-12-one ethylene acetal derivatives failed. The preparation of dihydroconkuressine, dihyd- 

The synthesis of 5,6-dihydro-1,3-oxazines in the androstane series as analogues of steroidal alkaloids has been reported. Treatment of the acetal (12a) with HN3-BF3 etherate gave the dihydro-1,3-oxazine (13) as major product and (14) as minor product. Catalytic hydrogenation, in neutral medium, of (13) led to the tetrahydro- 

Reagents i, NaBH4 ii, MeOH, HO iii, HCOOH, HCHO iv, HzH, HjOj 

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