反应详情

A mixture of 2,3-dihydro-3-[(phenylmethoxy)methyl]-1,4-dioxino[2,3-b]pyridine (0.0638 mol) in CH3OH (250 ml) was hydrogenated with palladium-on-carbon (10%, 2 g) as a catalyst. After uptake of hydrogen (1 equivalent), the catalyst was filtered off and the filtrate was evaporated. This fraction was purified by HPLC (eluent ethanol/methanol 60/40; column: Chiralpak AD 20 μm). Two fractions were collected and the solvent was evaporated, yielding 4.06 g of (S)-2,3-dihydro-1,4-dioxino[2,3-b]-pyridine-3-methanol (intermediate 2-a) ([α]D20=−34.33°; c=25.34 mg/5 ml in methanol) and 3.81 g of (R)-2,3-dihydro-1,4-dioxino[2,3-b]-pyridine-3-methanol (intermediate 2-b) ([α]D20=+32.740; c=22.60 mg/5 ml in methanol).

1. customthe filtrate was evaporated
2. customThis fraction was purified by HPLC (eluent ethanol/methanol 60/40; column: Chiralpak AD 20 μm)
3. customTwo fractions were collected
4. customthe solvent was evaporated