A. Cooper, D. Hodgkin
1968
Citations
1
Influential Citations
23
Citations
Journal
Tetrahedron
Abstract
Abstract The crystal and molecular structure of the steroid antibiotic, fusidic acid, has been determine by X-ray diffraction methods. The structure was solved from the 3-dimensional Patterson and Fourier syntheses and was refined by block-diagonal least-squares to a final R factor of 0·15. The steroid skeleton contains the unusual configurations 3α-OH, 4α-CH 3 , 5α-H, 8α·CH 3 , 9β-H, 10β-CH 3 , 11α-OH, 13α-H, 14β-CH 3 , 16β-OCOCH 3 and all ring junctions are trans fused with rings A and C syn to ring B. Rings A and C have chair conformations while ring B is a flattened boat. Comparison with other boat-shaped cyclohexane rings leads to the proposal that cyclohexane rings of this conformation may normally be flattened unless constrained to take up the more regular conformation usually assigned.