Abstract. Monoclinic, space group P21/c, a= 7.707 (2), b= 18.013 (7), c= 13.888 (4) A, fl= 125-75 (2) °, Z=4, M=270-37, Dc = 1.14 g cm -3, and Dm= 1"15 g cm -3.The atoms in the six-carbon alkyl group form a zigzag chain, and the molecule has a bent conformation which differs from the conformation of the highly active artificial estrogen diethylstilbestrol. The oxygen-oxygen distance is 8.63 A. Introduction.A crystal with dimensions of approximately 0.2 × 0.2 × 0.25 mm was used to measure the lattice parameters and intensities. The data showed systematic absences of k = 2n + 1 for 0k0 and l= 2n + 1