Crystal structure of bis-[3-meth-oxy-17β-estra-1,3,5(10)-trien-17-yl] oxalate.

In the title compound, C40H50O6, a symmetrical steroid oxalate diester, the dihedral angle between the CO2 planes of the oxalate linker is 61.5 (5)° and the C-C bond length is 1.513 (6) Å. The steroid B, C and D rings adopt half-chair, chair and envelope conformations, respectively, in both halves of the mol-ecule, which adopts an overall shallow V-shaped conformation. In the crystal, mol-ecules are linked by weak C-H⋯O inter-actions, forming a three-dimensional network

Reduction of 2-Nitro-5α-cholestan-3-one, Its Enol Tautomer and 2-Nitro-5α-cholest-2-en-3-amine Derivatives. Synthesis of Bis-Steroidal Pyrazines

Reduction of 2α-nitro-5α-cholestan-3-one (4), its enol tautomer (3a) and 3-acetylamino-2-nitro-5α-cholest-2-ene (2) was studied. The latter compound was reduced with zinc in acetic acid to 3β-acetylamino-5α-cholestan-2-one (8). The similar reaction of 3a or 4 led to 2α-amino-5α-cholestan-3-one (11a), that may be trapped as N-formyl derivative. When crude 11a was subjected to air oxidation, pyrazino[2',3':2,3;5',6':2,3]bis(5α-cholestane) (9) was obtained.</jats:p