A CHIRAL N-SULFONYLPHOSPHORAMIDE - SYNTHESIS AND X-RAY CRYSTAL-STRUCTURE OF A 1,3,2-OXAZAPHOSPHOLIDIN-5-ONE, A TRIVALENT ELECTRON-WITHDRAWING AMINO ACID-DERIVED PHOSPHORUS COMPOUND, AND SYNTHESIS OF ITS W(CO)(5) ADDUCT

Reaction of the amino acid derivative (S)-N-tolylsulfonylvaline with P hPCl2 and NEt3 gives in >90% yield a novel chiral phosphorus heterocyc le as a greater than 7:1 mixture of diastereomers. The X-ray crystal s tructure of the major isomer 7a shows that the isopropyl and phenyl gr oups are mutually cia. The IR spectrum of the W(CO)(5) adduct of 7a sh ows that the N-sulfonyl and carboxylate moieties make it a strongly el ectron-withdrawing ligand.