Publications [#233523] of Andrew T. McPhail

Journal Articles

  1. McPhail, AT; Luhan, PA; Wong Tschang, PS; Onan, KD, "Conformational preference of ring A in 3-oxo-∆5,10-steroids : X-ray crystal structure analysis of 17α-ethynyl-17β-hydroxyestr-5(10)-en-3-one (norethynodrel)", Journal of the Chemical Society Perkin Transactions 2January,, 1977(3), 379-383, Royal Society of Chemistry (RSC) [Gateway.cgi], [doi].
    (last updated on 2026/01/21)

    Abstract:
    The crystal structure and solid-state conformations of the title compound (5) have been established by X-ray analysis. Crystals are orthorhombic, space group P212121, with a= 21.593(13), b= 22.075(13), c= 7.015(8)Å, Z= 8. The structure was solved by direct methods and refined by least-squares calculations to R 0.046 over 2 572 statistically significant reflections from diffractometer measurements. The A rings in the two crystallographically independent molecules approximate to envelope conformations in which C(2) is displaced to the α-side in one and to the β-side in the other. Stabilization of the higher energy C(2) β-side envelope form is a consequence of the intramolecular hydrogen bonding arrangement in the crystal. The B ring shapes also differ slightly owing to conformational transmission effects. © 1977 by The Chemical Society.