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0 °C

Benzyl carbamate (4.89 g, 32 mmol, 2.3 equiv) was dissolved in 24 mL of n-PrOH. A solution of NaOH (1.3 g, 32 mmol, 2.3 equiv) in 36 mL of H2O was added to this stirred solution and the mixture was cooled at 0° C. in an ice water bath. To the mixture was then added tert-butyl hypochlorite (3.5 g, 32 mmol, 2.3 mmol). After stirring at 0° C. for 10 minutes, (DHQD)2PHAL (0.55 g, 0.7 mmol, 0.05 equiv) and 12 mL of n-PrOH was added. The reaction flask was immersed in a room-temperature water bath and stirred for 5 minutes. Methyl 4-methoxycinnamate (2.9 g, 14 mmol, 1.0 equiv) was added, followed by K2OsO2(OH)4 (207 mg, 0.56 mmol, 0.04 equiv). The reaction mixture was stirred for 2 hour at 0° C. by which it transformed into a pale yellow slurry. The precipitate was isolated by filtration. One wash with ice-cold EtOH—H2O (1:1, 5 mL) yielded product 2.21.1a as a white solid (3.5 g, 67%, >99% ee). MS m/z (M+Na+) 396

1. customThe reaction flask was immersed in a room-temperature water bath
2. stirringstirred for 5 minutes
3. stirringThe reaction mixture was stirred for 2 hour at 0° C. by which it
4. customThe precipitate was isolated by filtration
5. washOne wash with ice-cold EtOH—H2O (1:1, 5 mL)