3,4-dihydro-2H-pyran → HCID 19421209, compound

HRID 743920Notes

Reaction equation

HRID 743920 reaction equation
[CH:1]([C:3]1[CH:8]=[CH:7][C:6]([CH2:9][C:10]([OH:12])=[O:11])=[CH:5][CH:4]=1)=[CH2:2].[O:13]1[CH:18]=[CH:17][CH2:16][CH2:15][CH2:14]1>Cl.CCOCC>[CH:1]([C:3]1[CH:8]=[CH:7][C:6]([CH2:9][C:10]([O:12][CH:14]2[CH2:15][CH2:16][CH2:17][CH2:18][O:13]2)=[O:11])=[CH:5][CH:4]=1)=[CH2:2]

Participants

5

Reactant 2

HCID 80803,4-dihydro-2H-pyranHCID 11030140HCID 11030140, compound

Product 1

HCID 19421209HCID 19421209, compoundYield 70.8%

Reagents, catalysts & solvents 2

HCID 313Hydrochloric AcidCatalystHCID 3283Diethyl EtherSolvent

Conditions

Temperature
45 °C

Procedure

A mixture of 7 g (43 mmol) of 4-vinylphenylacetic acid, 12.0 g (142 mmol) of 3,4-dihydro-2H-pyran and 2 drops of 32% hydrochloric acid is warmed at 45° C. for 90 minutes in a 50 ml three-necked round-bottom flask fitted with magnetic stirrer and nitrogen blanketing system. 100 ml of ether are then added. The organic phase is then washed twice with 50 ml of 1 N sodium hydroxide solution in each case and twice with 50 ml of water in each case, dried over magnesium sulfate and evaporated, giving a colourless oil, which is recrystallized from three times the amount of n-hexane, giving 7.5 g (70% of theory) of tetrahydro-2H-pyran-2-yl 4-vinylphenylacetate having a melting point of 34° C. 1H-NMR (CDCl3, 300 MHz): δ [ppm] 7.4-7.1/m/4H 6.68/dd/1H 5.98/dd/1H 5.73/dd/1H 5.22/dd/1H -3.7/m/2H 3.64/s/2H 1.9-1.5/m/6H

Workup

  1. customfitted with magnetic stirrer
  2. washThe organic phase is then washed twice with 50 ml of 1 N sodium hydroxide solution in each case and twice with 50 ml of water in each case
  3. dry with materialdried over magnesium sulfate
  4. customevaporated
  5. customgiving a colourless oil, which
  6. customis recrystallized from three times the amount of n-hexane

Sources & evidence

ORD record
ord-42e3b7f972bb49a68d8ca27025863f83
Source dataset
uspto-grants-1996_09
Patent number
US05558978

Reaction notes

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