Hydrochloric Acid → 4-Hydroxy-1-(4-toluenesulfonyl)-D-prolinol

Participants

Reaction Conditions

Reaction Steps

To an ice-cold solution of 286.4 g (0.914 mole) of 4-hydroxy-(4-toluenesulfonyl)-D-proline ethyl ester (5) in 2.8 L of tetrahydrofuran was added 20 g (0.918 mole) of lithium borohydride in one portion. The mixture was stirred at 0° C. for 1 hour and then kept at a temperature below 25° C. overnight. The mixture was cooled to 0° C. and the pH adjusted to 3 with 6N hydrochloric acid (180 ml). The volume was reduced to 500 ml by rotary evaporation, and 1.5 L of water was added. The white precipitate was filtered, washed with cold water (500 ml) dried under reduce pressure to give 223.8 g (90%) of the title compound. M.P. =127° C. [α]D =36.66° (c=1.0, acetone) K.F. -6.55%.

Provenance & Evidence