Crystal and molecular structure of (4R,6R)-3-methoxycarbonyl-9,9-dimethyl-8-oxa-4-thia-1-azabicyclo[4.3.0]non-2-ene 4-oxide
Abstract
X-Ray crystallographic analysis of the title compound has established that there is substantial electron delocalisation involving the nitrogen atom and the ester group, with the bonds from the nitrogen atom nearly coplanar. The sulphur atom does not appear to be involved in the conjugation. The crystals are orthorhombic, space group P212121, with Z= 4 in a cell of dimensions a= 8·881 ± 0·005, b= 19·14 ± 0·01, c= 7·042 ± 0·005 Å. The structure was determined by Patterson and Fourier methods, by use of three-dimensional counter data, and refined by least-squares to R 6·7% for 1011 structure amplitudes.