carbon, and both its enantiomers have been found in nature. Enantiomericpure (+)-(1) and (−)-(1) were successfully prepared by racemic synthesis followed by enantiomeric separation in a chiral HPLC system. Their absolute configurations were clarified by the vibrational circular dichroism technique using their methyl esters 2 and lactones3. Their inhibitory activities against the interaction of p53–HDM2