ISOMERIZATION OF 2,3-DIESTER DERIVATIVE

摘要

PROBLEM TO BE SOLVED: To obtain a trans-2,3-diester derivative useful as a polyester monomer by isomerizing a cis-norbornane diester derivative in the presence of a specific base, optionally neutralizing a prepared isomer and successively diesterifying the isomer. ;SOLUTION: A cis-norbornane 2,3-diester derivative or cis- norbornane-2,3-diester derivative of formula I (R¹ and R² are each H or an alkyl; R¹ and R² are bonded to form a cycloalkyl, a cycloalkenyl, norbornane or norbornene; R³ is an alkyl) is isomerized with an alkaline(earth) metal alcoholate, carbonate or oxide to give a trans-isomer of formula II. Or the cis isomer of formula I is isomerized with an alkaline (earth) metal hydroxide, neutralized to give a compound of formula III, which is then diesterified with an acid catalyst in an alkyl alcohol.;COPYRIGHT: (C)1997,JPO