An Original Approach to the Synthesis of Phosphorus—Carbon Heterocycles — The 3‐Oxo‐2,3‐dihydro‐1,3‐oxaphospholes.

Abstract

The synthesis of new highly functionalized phosphorus heterocycles, the 3-oxo-2,3-dihydro-1,3-oxaphospholes, was achieved by a cyclization reaction involving malonic enolates as 1,3-O,C-dinucleophiles and phosphorus compounds, such as (chloromethyl)phosphinic chlorides or alkyl (chloromethyl)phosphonochloridates, as 1,2-dielectrophiles. Owing to the structural restriction that results from the cyclic structure, the 1H NMR spectra reveal extreme values of 2JP,H coupling constants that are sensitive to the HCPO dihedral angle. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)