(-)-Herbertenediol (3) which is regarded as a biosynthetic precursor of mastigophorenes A and B has been effectively synthesized from (R)-1,2-dimethyl-2-cyclopentene carboxylic acid by applying an intramolecular Heck reaction to the construction of the quaternary carbon center, and then horseradish peroxidase-catalyzed oxidative coupling of 3 has given rise to (-)-mastigophorenes A and B. Mastigophorenes A and B have been found to exhibit significant neuroprotective activity in primary cultures of fetal rat cortical neurons. (C) 2001 Elsevier Science Ltd. All rights reserved.