At RT, 1.5 g of rac-tert-butyl (2-hydroxy-3-phenoxypropyl)carbamate (5.6 mmol, 1 equivalent), 0.99 g of phthalimide (6.73 mmol, 1.2 equivalents) and 2.21 g of triphenylphosphine (8.4 mmol, 1.5 equivalents) were initially charged in 23 ml of dry tetrahydrofuran. 1.70 ml of diisopropyl azodicarboxylate (8.4 mmol, 1.5 equivalents) were added dropwise, and the mixture was stirred at RT for 2 h. LC/MS showed complete conversion of the reaction. The reaction mixture was concentrated and purified by chromatography on silica gel (Biotage Isolera; cyclohexane/ethyl acetate gradient as mobile phase). This gave 1.08 g of the title compound (48% of theory).
