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The Crystal and Molecular Structure of 3‐Oxo‐17β‐acetoxy‐Δ 4 ‐14α‐methyl‐8α, 9β, 10α, 13α‐estrene
Author(s) -
Koyama Gunji
Publication year - 1974
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19740570211
Subject(s) - chemistry , orthorhombic crystal system , ring (chemistry) , diffractometer , crystallography , crystal structure , crystal (programming language) , cyclohexane conformation , r value (soils) , x ray crystallography , stereochemistry , diffraction , hydrogen bond , molecule , physics , organic chemistry , computer science , programming language , structural engineering , optics , subgrade , engineering
The crystal and molecular structure of 3‐oxo‐17β‐acetoxy‐Δ 4 ‐14α‐methyl‐8α, 9β, 10α, 13α‐estrene, C 21 H 30 O 3 , has been determined by X‐ray diffraction analysis. The crystals belong to the orthorhombic space group P2 1 2 1 2 1 , with the cell dimensions a = 12.093 Å, b = 19.667 Å, c = 7.746 Å; Z = 4. Intensity data were collected at room temperature with an automatic four‐circle diffractometer. The structure was solved by direct methods and the parameters were refined by least‐squares analysis. All the hydrogen atoms were included in the refinement. The final R value was 0.038 for 1413 observed reflections. The conformation of ring A is intermediate between a half‐chair and a 1, 2‐diplanar form. The hydrogens at C(9) and C(10) are anti , the B/C ring junction is trans , and rings B and C adopt chair conformations. Ring D is cis fused and is halfway between C 2 and C s forms.