反应详情

Methyl 3-methyl-4-oxo-tetrahydro-2H-pyran-3-carboxylate (2.33 g, 13.53 mmol) was dissolved in toluene (150 mL) and treated with R-(+)-α-methylbenzylamine (3.96 mL, 2.3 eq) and ytterbium (III) trifluoromethanesulfonate (252 mg, 0.03 eq). The mixture was heated to reflux under Dean-Stark conditions overnight, and then concentrated to provide crude methyl 3-methyl-4-((R)-1-phenylethylimino)-tetrahydro-2H-pyran-3-carboxylate that was used in the next step without further purification.

1. temperatureThe mixture was heated
2. temperatureto reflux under Dean-Stark conditions overnight
3. concentrationconcentrated