The present invention provides a process for producing an optically active 2-allylcarboxylic acid derivative, which is useful as a pharmaceutical intermediate, from readily available and inexpensive starting materials by the process which can be practiced on a commercial scale in a simple and easy manner, and certain 2-allylcarboxamide derivatives, which are novel and important intermediates in that process.An N-allylcarboxamide derivative undergoes rearrangement reaction diastereoselectively in the presence of a base to give a 2-allylcarboxamide derivative, the resulting derivative is subjected to a carbamation reaction and solvolysis to give an optically active 2-allylcarboxylic acid ester, and then the ester obtained is stereoselectively hydrolyzed using an enzyme to produce 2-allylcarboxylic acid having a high optical purity. In addition, the present invention provides a 2-allylcarboxamide derivative compound which is a novel intermediate in the process of the present invention.