2-(triphenyl-lambda5-phosphanylidene)acetamide

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

Procedure: 4.0 g (11 mmol) of t-butyl(3S,4S)-1-(2,4-dimethoxybenzyl)-4-formyl-2-oxo-3-azetidinecarbamate are dissolved in 300 ml of methylene chloride and the solution obtained is treated dropwise with a solution of 3.9 g (12 mmol) of carbamoylmethylene-triphenylphosphorane in 100 ml of methylene chloride. After 1 hour, the mixture is filtered and the crystals obtained are washed with methylene chloride. There are obtained 3.6 g (81%) of t-butyl(3R,4S)-1-(2,4-dimethoxybenzyl)-4-[(E)-2-carbamoylvinyl]-2-oxo-3-azetidinecarbamate of melting point 270° C. the solution obtained the mixture is filtered the crystals obtained are washed with methylene chloride

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

Procedure: 4.0 g (11 mmol) of t-butyl (3S,4S)-1-(2,4-dimethoxybenzyl)-4-formyl-2-oxo-3-azetidinecarbamate are dissolved in 300 ml of methylene chloride and the solution obtained is treated dropwise with a solution of 3.9 g (12 mmol) of carbamoylmethylene-triphenylphosphorane in 100 ml of methylene chloride. After 1 hour, the mixture is filtered and the crystals obtained are washed with methylene chloride. There are obtained 3.6 g (81%) of t-butyl (3R,4S)-1-(2,4-dimethoxybenzyl)-4-[(E)-2-carbamoylvinyl]-2-oxo-3-azetidinecarbamate of melting point 270° C. the solution obtained the mixture is filtered the crystals obtained are washed with methylene chloride