In the title mol-ecule, C(21)H(16)Cl(2)O(2)S, the five-membered ring is rotationally disordered between two orientations in a 1:1 ratio. In the crystal structure, weak inter-molecular C-H⋯O hydrogen bonds link mol-ecules related by translation along the a axis into chains, which are further combined into layers parallel to the bc plane via C-H⋯π inter-actions. The crystal studied was a racemic ...

The conformational studies in solution and the solid state of substituted 6-methyl-4-hydroxy-2-pyrones indicated that substitents on 4-hydroxy group clearly favored s- cis arrangement towards formal double bond. steady NOE measurements kinetic tert -butyl, trimethylsilyl trimethylstannyl derivatives showed a marked preference for this conformation solution. structures determined by X-ray diffra...

Reaction of 2-(4-chloro-3,3,7-trimethyl-2,3-dihydro-1H-indol-2-yl-idene)propane-dial with hydroxyl-amine gives the title compound, C(14)H(14)ClN(3)O, in which the ring N atom is essentially planar [sum of angles around the ring N atom = 361°], indicating conjugation with the 2-cyano-acryl-amide unit. The orientation of the acetamide group arises from intra-molecular hydrogen bonding between the...