Ethyl 3-phenyl-2-ethoxycarbonyl-2-(2-tetrahydropyranyloxy)-propanoate → Ethyl 3-phenyl-2-hydroxy-2-ethoxycarbonyl-propanoate
反応式
[C:1]1([CH2:7][C:8]([C:21]([O:23][CH2:24][CH3:25])=[O:22])([O:14]C2CCCCO2)[C:9]([O:11][CH2:12][CH3:13])=[O:10])[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1>CCO>[C:1]1([CH2:7][C:8]([OH:14])([C:21]([O:23][CH2:24][CH3:25])=[O:22])[C:9]([O:11][CH2:12][CH3:13])=[O:10])[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=1参加物
3
実験手順
25 mg of pTS acid are added to a solution of ethyl 3-phenyl-2-ethoxycarbonyl-2-(2-tetrahydropyranyloxy)-propanoate (6 g) in EtOH (25 ml). After 12 hours at r.t., the solvent is evaporated under vacuum, the mixture is partitioned between water and AcOEt; the organic phase is separated, dried, concentrated to small volume. The residue is adsorbed on SiO2 (40 g); by elution with 90:10 cyclohexane:AcOEt, 4.3 g of ethyl 3-phenyl-2-hydroxy-2-ethoxycarbonyl-propanoate, oil, are obtained. I.R.: 3500, 3000, 1740, 1600 cm-1 ; HNMR (CDCl3) δ (TMS): 1.2-1.35 t, 3.35 s, 3.15 s, 4.2-4.3 q, 7.25 s.