p-Toluenesulfonic acid → HCID 20191510, compound

HRID 2118944Notes

Reaction equation

HRID 2118944 reaction equation
C(OC(=O)CC(C)=O)C.N1CCCCC1.[CH2:16]([O:18][C:19](=[O:30])[C:20]([C:27](=[O:29])[CH3:28])=[CH:21][CH:22]([CH3:26])[CH2:23][CH2:24][CH3:25])[CH3:17].C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1>[C:19]([C:20]1[CH2:21][C:22]([CH3:26])([CH2:23][CH2:24][CH3:25])[O:29][C:27]=1[CH3:28])([O:18][CH2:16][CH3:17])=[O:30]

Participants

6

Reactant 4

HCID 6101p-Toluenesulfonic acidHCID 8082PiperidineHCID 8868Ethyl AcetoacetateHCID 54065200HCID 54065200, compound

Product 1

HCID 20191510HCID 20191510, compound

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Conditions

Temperature
120 °C

Procedure

4-Carbethoxy-2,5-dimethyl-2-propyl-2,3-dihydrofuran was prepared by the acid-catalyzed rearrangement of ethyl-2-acetyl-4-methyl-2-heptenoate. The ethyl-2-acetyl-4-methyl-2-heptenoate was obtained by reacting 390 grams (3 moles) ethylacetoacetate with 300 grams (3 moles) 2-methylvaleradehyde in the presence of a small amount (10.2 grams; 0.12 mole) piperidine. For the rearrangement, 100 grams (0.47 mole) of the ethyl-2-acetyl-4-methyl-2-heptenoate was combined with 4.4 grams (0.023 mole) p-toluenesulfonic acid and 100 mls toluene. The mixture was heated at reflux (120° C.) for about 2 hours and worked up in accordance with the procedure of Example XXIV. Short path distillation of the crude product yielded 4-carbethoxy-2,5-dimethyl-2-propyl-2,3-dihydrofuran (B.P. 98°-100° C. at 2.5 mm Hg). The product had a pleasing cis-jasmine-like (jasmone, celery, jasmine absolute) odor. The structure ##STR25## was confirmed by infrared and nuclear magnetic resonance spectroscopy.

Workup

  1. temperatureThe mixture was heated
  2. distillationShort path distillation of the crude product

Sources & evidence

ORD record
ord-b668c45b77b44f989ae02181a4b1cabb
Source dataset
uspto-grants-1987_07
Patent number
US04681703

Reaction notes

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