反应详情

A solution of diethylazodicarboxylate (7.8 g) in DME (40 ml) was added dropwise under N2 to a stirred mixture of the product from step (a) (10.5 g), the product from step (c) (8.0 g) and triphenylphosphine (11.7 g) in DME (400 ml). When addition was complete, the mixture was stirred at room temperature for 17 hours, then evaporated in vacuo and the residue crystallised from ethanol/ether (1:4 v/v) to give the desired product as a pale yellow solid (12.7 g), [α]D25 -97.8° (c=0.50, MeOH).

1. additionWhen addition
2. customevaporated in vacuo
3. customthe residue crystallised from ethanol/ether (1:4 v/v)