PURPOSE: To provide new 2-naphthyl carbapenems that are useful intermediate of antibacterial agent.

CONSTITUTION: The compound of formula I, for example, (5R,6S)-2-(1- hydroxymethyl-3-naphtyl)-6-[1R-(allyloxycarbonyl oxy)ethyl]carbapen-2-em-3- carboxylic acid allyl ester is produced by allowing the compound of formula II to react with the compound of formula III. In the formula I, R is H or CH3; R1, R2 are each H, CH3, C2H5, CH(CH3)2, CH2OH, CH(OH)CH3, CH(OH), CH2F, CF2CH3, etc.; Ra is H, CF3, a halogen, alkoxy, OH, O(C=O)R5 {R5 is an alkyl, phenyl, S(O)nR5 [(n) is 0-2]}, azide, formyl, CN, SCN, SCF3, tetrazolyl, etc.; M is H, an esterification group, alkali metal, etc.