ChemInform Abstract: Structure of 6α-Methylprogesteron-17α-yl Pivalate

C27H40O4, Mr = 428.6, orthorhombic, P2(1)2(1)2(1), a = 9.821(3), b = 25.766(6), c = 9.802(3) A, V = 2480(2) A3, Z = 4, Dx = 1.15 g cm-3, lambda(Mo K alpha) = 0.71073 A, mu = 0.70 cm-1, F(000) = 936, T = 295 K, final R = 0.063 for 2778 observed reflections. The A ring assumes a normal 1 alpha,2 beta-half-chair conformation. The progesterone side chain has a conformation typical of 17 alpha-ester steroids; the C(16)-C(17)-C(20)-O(20) torsion angle is -17.9(5) degrees.