Conformational analysis of progestational agents: 11β-fluoro-19-nor-17α-pregn-4-en-20-yn-17β-ol

Abstract

Successive cross-linking would form polymer molecules with chain axes parallel to a. There is sufficient freedom for the diacetylene segments of 3,5-octadiyne-l,8-diol to be rearranged during polymerization without the series of hydrogen bonds (illustrated by the broken lines in Fig. 3) being disrupted. This contrasts significantly with the behaviour of 2,4-hexadiyn-1-ol (Fisher, Batchelder & Hursthouse, 1978) where rather severe hydrogen-bonding restrictions at one end of each monomer molecule affect the polymerization process. Crystallographic studies of polymeric 3,5-octadiyne-1,8-diol are in progress.We thank C. Galiotis for his help in synthesizing the octadiyne-diol and Dr D. Bloor for useful discussions. This work was supported by grants from the SRC and The Royal Society. Abstract. C20H27FO, M r = 302.4, monoclinic, P2~, a = 10.2844 (7), b = I1.2118 (6), c = 7.2248(4) A, fl= 94.604 (5) ° (2 = 1.5418 A, T = room temperature), V= 830.4 A 3, Z = 2, px= 1.210g cm -3.The llflfluoro substituent places about the same steric strain on the molecule as H. The result in overall conformation is essentially the same as the unsubstituted compound without the bowing caused by other 11 fl substituents.

Structure of the methanol solvate of 13-ethyl-18,19-dinor-17α-pregn-4-en-20-yn-17β-ol (13-ethyl-18-norlynestrenol)

“…The bond lengths and angles of ELYN correspond well to those observed in other lynestrenol derivatives (Griffin, Duax & Weeks, 1984). The overall conformation of ELYN is very similar to that of the parent compound lynestrenol (Rohrer, Lauffenburger, Duax & Zeelen, 1976) and of 1 lfl-fluorolynestrenol (Rohrer, Duax & Zeelen, 1978). (6) 0.3384 (3) 0.8655 (7) 0.7037 (3) 0.070 (1) C (7) 0.3015 (3) 0.8998 (7) H...H contact is 2.185 (6)A.…”

Quantitative Structure−Activity Relationship Studies of Progesterone Receptor Binding Steroids

“…However, in the latter compounds, the ethyl groups are known to occupy an anti conformation that is not possible in 56 . Moreover, steric repulsion causes the steroid to adopt a convex shape, as demonstrated by X-ray structures. , …”