SYNTHESIS OF DIALKYL(PYRROLIDIN-2-YL)-PHOSPHONATES BY MERCURIC ACETATE PROMOTED CYCLIZATION OF ALPHA-AMINOALKENYLPHOSPHONATES - REGIO AND STEREOCHEMICAL ASPECTS

A new series of dialkyl(pyrrolidin-2-yl)phosphonates was synthesized b y regiospecific intramolecular aminomercuration of alpha-amino alkenyl phosphonates followed by sodium borohydride reduction. The formation o f dialkyl (2,5-dialkyl pyrrolidin-2-yl) and dialkyl (5-alkyl pyrrolidi n-2-yl)phosphonates was stereoselective and the stereochemistry of dia stereomers was assigned using X-ray analysis and H-1, C-13 and P-31-NM R data. EPR evidence for the production of free radicals during the bo rohydride reduction of the intermediate organomercurials was achieved by spin-trapping experiments.