Givaudan Corporation

Hans-Jakob Wild

Ulrich Huber

Peter M Muller

The invention concerns the novel compound, 4-methyl-3-pentyl-2 (5H)-furanone, I, a process for the manufacture of I and fragrance and flavor compositions containing I. ##STR1##

4-methyl-3-pentyl-2(5H)-furanone

A process for the manufacture of 3-hydroxy-2-alkyl-4-pyrones of formula I is provided. ##STR1## The process comprises cyclizing a compound of formula II, ##STR2## an acidic medium and hydrolyzing the ester formed thereby to produce compound I. R.sup.1 represents methyl or ethyl; R.sup.2 represents lower alkanoyl or optionally substituted benzoyl; R.sup.3 represents --OH or --NR.sup.4 R.sup.5 ; and, R.sup.4 and R.sup.5 may be alike or different and represent lower alkyl. The pyrones of formula I wherein R.sup.1 represents methyl or ethyl are known flavorants and odorants.

Substituted diones as intermediates for a process for the manufacture of

A process for the manufacture of 3-hydroxy-2-alkyl-4-pyrones of formula I is provided. ##STR1## The process comprises cyclizing a compound of formula II, ##STR2## in acidic medium and hydrolyzing the ester formed thereby to produce compound I. R.sup.1 represents methyl or ethyl; R.sup.2 represents lower alkanoyl or optionally substituted benzoyl; R.sup.3 represents --OH or --NR.sup.4 R.sup.5 ; and, R.sup.4 and R.sup.5 may be alike or different and represent lower alkyl. The pyrones of formula I wherein R.sup.1 represents methyl or ethyl are known flavorants and odorants.

Process for the manufacture of .gamma.-pyrones

The instant invention provides a new and improved method of preparing .alpha.-hydroxycarbonyl compounds, particularly substituted cyclopent-2-en-2-ol-1-ones and substituted 3-hydroxy-2(5H)-furanones. The novel sequence involves a number of novel intermediates including substituted 2-cyanocyclopentanones, substituted 2-cyano-2-hydroxycyclopentanones, and 2-cyano-2-hydroxyvalero-.gamma.-lactones.

Novel intermediates for the preparation of .alpha.-hydroxycarbonyl

The instant invention provides a new and improved method of preparing .alpha.-hydroxycarbonyl compounds, particulary substituted cyclopent-2-en-2-ol-1-ones and substituted 3-hydroxy-2(5H)-furanones. The novel sequence involves a number of novel intermediates including substituted 2-cyanocyclopentanones, substituted 2-cyano-2-hydroxycyclopentanones, and 2-cyano-2-hydroxyvalero-.gamma.-lactones.

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Wolfhausen, Switzerland

Hans-Jakob Wild