反应详情

To a 60 ml dichloromethane solution of ethyl 7-hydroxychromane-2-carboxylate (1.32 g, 5.9 mmol), 2-bromoethanol (0.84 ml, 11.9 mmol), and triphenylphosphine (3.12 g, 11.9 mmol) was added diisopropyl azodicarboxylate (2.34 ml, 11.9 mmol) dropwise upon cooling in an ice-water bath. After stirring at rt overnight, the solvent was removed under reduced pressure, and the residue was chromatographed on silica gel eluting with 10% AcOEt/hexanes to give the title compound 1.27 g (65%).

1. temperatureupon cooling in an ice-water bath
2. customthe solvent was removed under reduced pressure
3. customthe residue was chromatographed on silica gel eluting with 10% AcOEt/hexanes