Coordinative resolution of 1-phenyl- and 1-naphthyl-3-methyl-3-phospholene 1-oxides with calcium hydrogen O, O′-dibenzoyl-(2 R,3 R)-tartrate or calcium hydrogen O, O′-di- p-toluyl-(2 R,3 R)-tartrate

Abstract

A convenient and efficient resolution of 1-phenyl- 1a and 1-naphthyl-3-methyl-3-phospholene 1-oxides 1b is described. The separation is based on the finding that the calcium hydrogen O, O′-dibenzoyl-(2 R,3 R)-tartrate 2 or calcium hydrogen O, O′-di- p-toluyl-(2 R,3 R)-tartrate 3 forms diastereomeric coordination complexes with the enantiomers of phospholene 1-oxides 1a and 1b. The stereostructure of the supramolecular formation of Ca( 1a) 2(H-DBTA) 2 and absolute configuration of the 3-phospholene oxide 1a were elucidated by single crystal X-ray crystallography.