Synthesis of 4-hydroxy-7,8-dimethoxyisochroman-3-one and its plant growth-regulating properties on tobacco (Nicotiana tabacum cv. Petit Havana).

The synthesis of 6,7-dimethoxy-4-hydroxyisochroman-3-one 10 from 2,3-dimethoxytoluene (11) via glyoxylate 12 is reported. Compound 10 strongly inhibited vegetative growth of tobacco plants, whereas developmental patterns (protein levels, protein profile, pigments, and chlorophylls) were not affected. Morphological changes were observed in the leaves of the treated plants.