Methyl vinyl ketone → Piperitenone

HRID 1657542

Reaktionsgleichung

Reaktionsgleichung von HRID 1657542
[CH:1]([C:3]([CH3:5])=O)=[CH2:2].O=[C:7]([CH:9]=[C:10]([CH3:12])[CH3:11])[CH3:8].[OH-:13].[K+]>O1CCCC1>[CH3:5][C:3]1[CH2:8][CH2:7][C:9](=[C:10]([CH3:12])[CH3:11])[C:2](=[O:13])[CH:1]=1

Komponenten

5

Edukt 3

HCID 6570Methyl vinyl ketoneHCID 8858Mesityl oxideHCID 14797Potassium Hydroxide

Produkt 1

HCID 381152Piperitenone

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 8028TetrahydrofuranLösungsmittel

Versuchsvorschrift

A similar process is described by S. Ohshiro et al (Yakugaku Zasshi, 88, 417 (1968)). Here again the reaction of methyl vinyl ketone with excess mesityl oxide takes place in the presence of potassium hydroxide powder but without addition of tetrahydrofuran as the solvent. The piperitenone obtained is converted into a mixture of menthone and isomenthone by catalytic hydrogenation. However, in this process of yields of piperitenone are again only about 53%; furthermore, using this process the menthone/isomenthone mixture is obtained in only 64.6% yield and in a purity of only 89.8%. For this reason, the further reaction to give pure methol has to be carried out in an involved manner via menthone-oxime (Jap. Pat. No. 7,009,375) and menthylamine, which makes it doubtful whether the process is suitable for commercial operation.

Quellen und Nachweise

ORD-Eintrag
ord-59c08284180f4bc499ad7c1ffbcc7286
Quelldatensatz
uspto-grants-1976_06
Patentnummer
US03960970

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