L-Proline-Catalysed Unusual Product Formation from the Reaction of 4- Hydroxydithiocoumarin and Aldehydes through a Pseudo-Three-Component Reaction

Abstract

A convenient and highly efficient synthetic protocol is reported for the synthesis of hitherto unreported thiopyrano{2,3- b :6,5- b ′}bis(thiochromene)-12,14(13 H )-diones by a domino pseudo-three-component reaction utilizing 4-hydroxydithiocoumarin and aldehydes. Single-crystal X-ray crystallographic analysis of the 13-phenyl-12 H -thiopyrano[2,3- b :6,5- b ′]bis(thiochromene)-12,14(13 H )- dione derivative shows a layered structure that is stabilized by the unexpected C–S···π interactions.