Process for preparing 2-cyclopentenone derivatives
申请人:Sumitomo Chemical Company, Limited
公开号:US04496767A1
公开(公告)日:1985-01-29
A novel process for preparing 2-cyclopentenones of the formula: ##STR1## wherein R.sub.1 is hydrogen, alkyl or alkenyl and R.sub.2 is alkyl, alkenyl, alkynyl, cycloalkyl, aryl or aralkyl, which comprises esterifying a mixture of a 3-hydroxy-4-cyclopentenone of the formula: ##STR2## wherein R.sub.1 and R.sub.2 are each as defined above and a 4-hydroxy-2-cyclopentenone of the formulas: ##STR3## wherein R.sub.1 and R.sub.2 are each as defined above with an aliphatic carboxylic acid to give a mixture of the 4-hydroxy-2-cyclopentenone (III) and the cyclopentenone ester of the formula: ##STR4## wherein R.sub.1 and R.sub.2 are each as defined above and R is hydrogen or C.sub.1 -C.sub.4 alkyl and subjecting the resulting mixture to reduction.
A process for preparing cyclopentenone derivatives of the formula: ##STR1## wherein R.sup.1 is hydrogen, lower alkyl or lower alkenyl, R.sup.2 is hydrogen, lower alkyl, lower alkenyl, lower alkynyl, cycloalkyl, substituted or unsubstituted aryl or substituted or unsubstituted ar(lower)alkyl and A is the residue of a nucleophilic agent from which a hydrogen atom is excluded, which comprises reacting a 3-hydroxy-4-cyclopentenone compound of the formula: ##STR2## wherein R.sup.1 and R.sup.2 are each as defined above with a nucleophilic agent of the formula A--H (III) wherein A is as defined above. The cyclopentenone derivatives of the formula (I) are useful as pharmaceuticals, agricultural chemicals, perfumes and as intermediates for the preparation of agricultural chemicals, pharmaceuticals and perfumes.