Lithium hydroxide, monohydrate → 4-METHYLTETRAHYDRO-2H-PYRAN-4-CARBOXYLIC ACID

Participants

Reaction Steps

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).

Provenance & Evidence