Title:
PRODUCTION OF TETRAHYDROISOALPHA AND HEXAHYDROISOALPHA ACIDS
Document Type and Number:
Japanese Patent JP2525133
Kind Code:
B2
Abstract:
PURPOSE: To obtain high-purity tetrahydroisoalpha and hexahydroisoalpha acids useful as hop flavors in a high yield by hydrogenating an isoalpha acid, a dihydroisoalpha acid, or a mixture thereof.
CONSTITUTION: An isoalpha acid of formula I (wherein R is isopropyl, isobutyl, or sec-butyl), a dihydroisoalpha acid of formula II, or a mixture thereof is hydrogenated in an inert protonic solvent (e.g. ethanol) contg. a hydrogen gas in the presence of a noble metal catalyst (e.g. Pd-C) at a pH of 5-12 under an atmospheric pressure to 141 kg/cm2 (2,000 psi) at 50-200°C to give a tetrahydroisoalpha acid of formula III (wherein X is C=O), a hexahydroisoalpha acid of formula III (wherein X is CHOH), or a mixture thereof.
Inventors:
BURUUSU ARAN HEI
Application Number:
JP15475394A
Publication Date:
August 14, 1996
Filing Date:
July 06, 1994
Export Citation:
Assignee:
PFIZER
International Classes:
B01J23/44; C07C45/62; C07C45/67; C07C49/707; C07B61/00; C07C49/743; C12C3/00; C12C3/12; C12C5/00; C12C; (IPC1-7): C07C49/707; C07C45/62
Attorney, Agent or Firm:
Kyozo Yuasa (4 outside)