(R)-2-tert-butoxycarbonylamino-3-hydroxy propionic acid → (R)-3-(tert-Butoxy)-2-((tert-butoxycarbonyl)amino)propanoic acid

Participants

Reaction Conditions

Reaction Steps

To an ice-cooled solution of N-BOC-D-serine (10 g, 48.7 mmol) in methylene chloride (50 ml) was added N,N′-diisopropyl-O-tert-butylisourea (35 ml, 3.5 M) via addition funnel, over 30 min. The reaction mixture was maintained at 0° C. for 2 hrs and then warmed to room temperature over night. The material was again cooled to 0° C. and a second portion of N,N′-diisopropyl-O-tert-butylisourea (28 ml, 3.5 M) was added. The material was stirred for 2 hrs at 0° C. and then warmed again to room temperature over night. Purification by flash silica gel chromatography using (20%) ethyl acetate/hexanes as eluant gave O-tert-butyl-N-BOC-D-serine (7.97 g) as a viscous oil which solidified on standing.

Provenance & Evidence