organic compounds
The absolute configuration has been determined for the bicyclic title compound, C14H17N7O7S, an intermediate in the synthesis of fixed chiral bis(1,2-aminohydroxy) compounds. In the crystal structure, the chair conformation of the seven-membered lactam ring exhibits four axial heteroatom substituents. The fused five-membered thiazolidine ring prevents inversion of the seven-membered iduronic acid ring derivative to the thermodynamically more favourable chair conformation with four equatorial substitutions.
organic compounds
The absolute configuration has been determined for the title compound, C21H27NO9S2·C7H8. The compound is a precurser in the synthesis of bicyclic dipeptide isosteres based on mannuronic acid. The seven-membered lactam ring adopts a rigid chair conformation.