2-diethoxyphosphoryl-N-methylacetamide

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The same operation as in Reference Example 4-1) was carried out by using (2S,4S)-N-allyloxycarbonyl-2-hydroxymethyl-4-tritylthiopyrrolidine (the compound obtained in the Reference Example 3-1); 4.60 g, 10.0 mmol), dimethyl sulfoxide (1.99 ml, 28.0 mmol), oxalyl chloride (1.28 ml, 15.0 mmol), triethylamine (6.98 ml, 50.0 mmol), 2-(diethylphosphono)-N-methylacetamide (2.32 g, 11.0 mmol) and 60% sodium hydride (420 mg, 10.5 mmol), followed by flash column chromatographic purification on silica gel (Wakogel® C-300, 100 ml, elution with hexaneethyl acetate 1:2) to give the title compound (4.60 g, 89.7% yield). obtained in the Reference Example 3-1)