Benzaldehyde → (R)-Tetrahydro-3-phenyl-3H,5H-pyrrolo[1,2-c]oxazol-5-one

Participants

Reaction Steps

A mixture of 5-hydroxymethyl-2-pyrrolidone (85.0 g), benzaldehyde (98.0 g), p-toluenesulfonic acid (1.6 g) and toluene (500 ml) was heated to reflux using a Dean-Stark water separator and an oil bath, with vigorous stirring. After nine hours, the collection of water stopped and the cooled reaction mixture was washed with 5% sodium bicarbonate solution (2×50 ml), saturated sodium bisulfite solution (4×50 ml), water (2×50 ml) and brine (1×50 ml). The toluene solution was dried over anhydrous magnesium sulfate and the solvent removed on a rotary evaporator. The residue obtained was distilled, 145°-150° C./0.1 mm Hg to give the title compound as an oil (129.0 g). [α]D =+269.6° (chloroform; c=1). TLC single spot at Rf =0.5 (silica gel, ethyl acetate-hexane; 4:1 UV and iodine).

Provenance & Evidence