反应详情

150 g of the 98:2 mixture of (4S,5S) and (4S,5R) isomers of methyl 4-benzyl-2-oxo-oxazolidine-5-carboxylate from Example 7B) are added at 15°-20° C. over 1.5 hours to a stirred solution of 20.8 g of NaBH4 in 360 ml of ethanol and stirred for 2 hours. The suspension is treated with 540 ml of water at 20° C. and the pH is brought to 7 with 165 ml of 3N hydrochloric acid. The suspension is stirred at 22° C. for 2.5 hours, left to stand at 4° C. for 18 hours, then filtered and the residue is washed with water and dried to give 111.6 g (84%) of 99% (4S,5S)-4-benzyl-5-hydroxymethyl-oxazolidin -2-one, m.p. 167.3°-168.9° C., [α]D20 : -79.4 ° (1% in methanol).

1. stirringThe suspension is stirred at 22° C. for 2.5 hours
2. waitleft
3. waitto stand at 4° C. for 18 hours
4. filtrationfiltered
5. washthe residue is washed with water
6. customdried