3,4-dihydro-2H-pyran → 2-Propanone, 1,3-bis[(tetrahydro-2H-pyran-2-yl)oxy]-

HRID 2288287Notes

Reaction equation

O[C:2]1([CH2:11][OH:12])[CH2:7][O:6][C:5]([OH:10])([CH2:8]O)C[O:3]1.O1[CH2:18][CH2:17][O:16][CH2:15][CH2:14]1.O1C=C[CH2:22][CH2:21][CH2:20]1.[C:25](=O)(O)[O-].[Na+]>C(Cl)Cl.C(N(CC)CC)C>[O:16]1[CH2:17][CH2:18][CH2:25][CH2:14][CH:15]1[O:12][CH2:11][C:2](=[O:3])[CH2:7][O:6][CH:5]1[CH2:8][CH2:22][CH2:21][CH2:20][O:10]1

Participants

Conditions

Temperature: 40 °C

Procedure

9 g of 2,5-dihydroxy-1,4-dioxane-2,5-dimethanol is introduced into 60 ml of dioxane and the suspension is taken to about 70° C. for 15 minutes then returned to ambient temperature. 20 ml of 3,4-dihydro 2H-pyran and 300 mg of monohydrated paratoluene sulphonic acid are then added and the temperature is maintained at about 40° C. then the whole is left for 16 hours at ambient temperature. The reaction medium is poured into a mixture of 300 ml of saturated sodium bicarbonate solution +10 ml of triethylamine and extraction is carried out 4 times with methylene chloride. The organic phase is washed with salt water and dried. After purification by passage through silica, eluting with cyclohexane-ethyl acetate: 8-2 with 0.5% of triethylamine, 17 g of expected product (pale yellow syrup) is obtained.

Workup

customthen returned to ambient temperature
waitthe whole is left for 16 hours at ambient temperature
washThe organic phase is washed with salt water
customdried
customAfter purification by passage through silica
washeluting with cyclohexane-ethyl acetate

Sources & evidence

ORD record: ord-a57ea696293640b7b2bc98ee9fc9159a
Source dataset: uspto-grants-2000_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06087509

Reaction notes

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