Sulfuric Acid → 2H-1-Benzopyran-6-ol, 3,4-dihydro-2-methoxy-2,5,7,8-tetramethyl-

HRID 268405

Reaction equation

HRID 268405 reaction equation
[CH3:1][C:2]1[C:3]([OH:11])=[C:4]([CH3:10])[C:5]([CH3:9])=[C:6]([CH:8]=1)[OH:7].C(OC)(OC)OC.OS(O)(=O)=O.C(C(C)=O)=C.[CH3:29][O:30][C:31]([CH:33]=[CH2:34])=[CH2:32].O=C(C)CCO.COC(OC)(C)C=C.COCCC(=O)C>CO>[OH:11][C:3]1[C:2]([CH3:1])=[C:8]2[C:6](=[C:5]([CH3:9])[C:4]=1[CH3:10])[O:7][C:31]([O:30][CH3:29])([CH3:32])[CH2:33][CH2:34]2

Participants

10

Reactant 8

HCID 1118Sulfuric AcidHCID 6570Methyl vinyl ketoneHCID 9005Trimethyl orthoformateHCID 12785TrimethylhydroquinoneHCID 993382-Methoxy-1,3-butadieneHCID 1115094-Hydroxy-2-ButanoneHCID 1388892-Butanone, 4-methoxy-HCID 130289103,3-Dimethoxybut-1-ene

Product 1

HCID 1037632H-1-Benzopyran-6-ol, 3,4-dihydro-2-methoxy-2,5,7,8-tetramethyl-

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

In the manner described in Example 1, 3.80 g (25 mmol) samples of trimethylhydroquinone were treated in 25 ml of methanol, 5.0 ml of trimethyl orthoformate, and 0.10 ml of 36 N aqueous H2SO4 with 50 mmole portions of the following methyl vinyl ketone substitutes: a, 2-methoxybutadiene; b, 3-ketobutanol; c, 3,3-dimethoxybutene (contaminated with about 20 percent 2-methoxybutadiene); and d, 4-methoxy-2-butanone. The reactions were monitored by tlc. Reactions a,c and d were complete after 24 hr and were worked up and dried in the manner of Example 1 to give (±)-6-hydroxy-2-methoxy-2,5,7,8-tetramethylchroman. In reaction b, a>50 percent conversion to (±)-6-hydroxy-2-methoxy-2,5,7,8-tetramethylchroman was indicated by tlc.

Workup

  1. customdried in the manner of Example 1

Sources & evidence

ORD record
ord-7499afe1cbc242abbe87599304411fec
Source dataset
uspto-grants-1976_03
Patent number
US03947473

Linked notes

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