Methanol → Tetrahydropyranyl ether

Participants

Reaction Steps

To a solution of 100.0 g (0.2557 mole) of methyl hyodeoxycholate and 5.68 g of p-toluenesulfonic acid in 2000 ml of p-dioxane was added 153.7 g (1.62 mole, 148.6 ml) of dihydropyran over a period of 30 min under argon atmosphere. After stirring overnight at room temperature, the pH of the solution was adjusted to approximately pH 8 by the addition of 55 ml of 50/50 methanol/29% ammonium hydroxide. The solution was concentrated to a yellow oil under reduced pressure and the residue stirred in heptane 4 hr, then filtered to remove the precipitated p-toluenesulfonic acid. The filtrate was heated with charcoal, filtered, and evaporated to yield 116.8 g (80%) of the di-tetrahydropyranyl ether as a colorless viscous oil.

Provenance & Evidence