An Original Approach to the Synthesis of Phosphorus-Carbon Heterocycles − The 3-Oxo-2,3-dihydro-1,3-oxaphospholes

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)