| 摘要 |
NEW MATERIAL:A compound expressed by formula I (R<1> and R<2> are alkyl optionally may be linked through the O or N atom to form a 5- - 6-membered ring: R<3> is 1-6C alkyl). EXAMPLE:2-Dimethylamino-3-methyl-2-cyclopentenon-1-one. USE:An intermediate for preparing a 2-hydroxy-3-alkyl-2-cyclopenten-1-one useful as a food perfume. The aimed compound can be obtained in high purity and yield by using the above-mentioned intermediate. PROCESS:A novel aminodiketone expressed by formula II is subjected to the ring closure in the presence of an alkali, e.g. NaOH, to afford the aimed compound expressed by formula I . The reaction is carried out usually at 20-40 deg.C while keeping the inside of the reaction system at >=12pH. The novel compound expressed by formula II can be obtained by subjecting a furan substitution product of furan expressed by formula II to the ring opening in the presence of an acid, e.g. HCl. |
