4-Methylmorpholine → tert-butyl ((2R,3R)-1-hydroxy-3-methoxybutan-2-yl)carbamate

Participants

Reaction Steps

To a cold solution (−15° C.) of BocThr(Me)OH (5.14 g, 22 mmol) in dichloroethane (22 mL) were successively added N-methyl morpholine (2.44 mL, 22 mmol) and isobutyl chloroformate (2.99 mL, 22 mmol). After one min, the precipitate was filtered and washed with dichloroethane (5×4 mL). The filtrate and washings were combined in a large three neck flask in an ice-salt bath. A solution of NaBH4 (1.26 g, 33 mmol) in H2O (11 mL) was added at once, proceeding a strong evolution of gas, followed by H2O (500 mL). The mixture was then extracted with EtOAc (5×150 mL). The combined EtOAc was dried (Na2SO4) and concentrated to give the titled compound (5 g). MS (MH+ 220).

Provenance & Evidence