Isochroman represent an important class of plant natural product of biological activity. There are several optically active isochroman derivatives that show remarkable pharmacological activities such as selective 5-HT1D, D1 agonist and D4 antagonist, which are promising for the treatment of migraines, Parkinson’s disease and schizophrenia respectively. There are also several natural 3-alkylisochroman derivatives of remarkable biological activity such as pseudodeflectusin which is a selective human cancer cytotoxin.