Ethylene Glycol → 6-Hydroxy-2,5,7,8-tetramethylchroman-2-acetic acid

HRID 2052583Notes

Reaction equation

HRID 2052583 reaction equation
C=C([CH2:6][CH2:7][C:8]1[C:13]([O:14][C:15](=O)[CH3:16])=[C:12]([CH3:18])[C:11]([CH3:19])=[C:10]([O:20]C(=O)C)[C:9]=1[CH3:24])CC#N.[OH-:25].[K+].[CH2:27]([OH:30])[CH2:28]O.Cl>O>[OH:20][C:10]1[C:11]([CH3:19])=[C:12]([CH3:18])[C:13]2[O:14][C:15]([CH2:28][C:27]([OH:30])=[O:25])([CH3:16])[CH2:6][CH2:7][C:8]=2[C:9]=1[CH3:24]

Participants

6

Reactant 4

HCID 174Ethylene GlycolHCID 313Hydrochloric AcidHCID 14797Potassium HydroxideHCID 203337993-Methylene-5-(2,4,5-trimethyl-3,6-diacetyloxy-phenyl)pentanenitrile

Product 1

HCID 55926-Hydroxy-2,5,7,8-tetramethylchroman-2-acetic acidYield 84%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Procedure

A mixture of 623 mg (1.89 mmoles) of the mixture of E- and Z-3-methyl-5-(2,4,5-trimethyl-3,6-diacetyloxyphenyl)-3-pentenenitrile and 3-methylene-5-(2,4,5-trimethyl-3,6-diacetyloxy-phenyl)pentanenitrile, 498 mg (7.70 mmoles) of 85% KOH, 5 ml of ethylene glycol and 0.5 ml of water was stirred and refluxed for 36 hr. The reaction mixture was cooled to room temperature, then poured into water. The pH of the solution was adjusted to 8 with 1 N aqueous HCl and the resulting mixture was extracted with two portions of ether (the extracts were discarded). The aqueous phase was acidified with 3 N aqueous HCl and worked-up with ether in the usual manner giving 421 mg (84%) of rac.-(6-hydroxy-3,4-dihydro-2,5,7,8-tetramethyl-2H-1-benzopyran-2-yl)acetic acid as a tan solid, mp 168°-170°.

Workup

  1. temperaturerefluxed for 36 hr
  2. extractionthe resulting mixture was extracted with two portions of ether (the extracts

Sources & evidence

ORD record
ord-31ed43d0447b4f2aa231ff9fad9776cb
Source dataset
uspto-grants-1980_01
Patent number
US04186138

Reaction notes

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