Propargyl alcohol → Tetrahydro-2-(2-propynyloxy)-2H-pyran

Temperature

0 °C

To a stirred solution of 112 g (2.0 mol.) of 3-hydroxy-1-propyne and 260 g (3.0 mol.) of dihydropyran in 1.20 liters of methylene chloride cooled to 0° C. in an ice bath, is added a solution of 20 mg of para-toluenesulfonic acid in 100 ml of methylene chloride, dropwise. The reaction mixture is stirred at 0° C. for one-half hour, and at ambient temperature for one hour. It is then poured into 200 ml of a 5% solution of sodium bicarbonate, the organic phase is separated, the aqueous phase extracted with 100 ml of methylene chloride, the combined organic phases washed with 100 ml of a solution of brine, dried over sodium sulfate, and evaporated under vacuum (12 mm) at 45° C. to give 300 g of crude product, which is purified by fractional distillation, bp 71°-73° C. (14 mm) to yield 250 g (89%) of a liquid.

1. customthe organic phase is separated
2. extractionthe aqueous phase extracted with 100 ml of methylene chloride
3. washthe combined organic phases washed with 100 ml of a solution of brine
4. dry with materialdried over sodium sulfate
5. customevaporated under vacuum (12 mm) at 45° C.
6. customto give 300 g of crude product, which
7. distillationis purified by fractional distillation, bp 71°-73° C. (14 mm)

ORD record

ord-7881561c615f42b1925fcc590a572dec

Source dataset

uspto-grants-1979_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04165331