反应详情

A solution of methyl 4-methyltetrahydro-2H-pyran-4-carboxylate (5.00 g, 31.6 mmol) in 1:1:1 dioxane/water/MeOH (60 mL) was treated with lithium hydroxide hydrate (5.31 g, 126 mmol) and stirred at RT overnight. The mixture was partially concentrated, diluted with water and EtOAc and acidified to pH=1 with 6M HCl. The layers were separated, the aqueous layer extracted with additional EtOAc (50 mL) and the combined organics were washed with brine, dried over Na2SO4 and concentrated to dryness to afford 4-methyltetrahydro-2H-pyran-4-carboxylic acid (4.61 g, 100%). 1H NMR (400 MHz, DMSO-d6): δ 12.29 (s, 1H), 3.65 (dt, J=11.8, 4.3 Hz, 2H), 3.33-3.32 (m, 2H), 1.87-1.86 (m, 2H), 1.35 (ddd, J=13.5, 9.9, 4.1 Hz, 2H), 1.13 (s, 3H).

1. concentrationThe mixture was partially concentrated
2. additiondiluted with water and EtOAc
3. customThe layers were separated
4. extractionthe aqueous layer extracted with additional EtOAc (50 mL)
5. washthe combined organics were washed with brine
6. dry with materialdried over Na2SO4
7. concentrationconcentrated to dryness