SYNTHESIS AND CYTOKININ ACTIVITY OF NEW ZEATIN DERIVATIVES

The analogue of zeatin bearing a vinylic fluorine atom and its geometr ical isomer were synthesized. The fluorine atom exerts a favorable inf luence on cytokinin activity in the fluoro analogue of cis-zeatin, but not in the fluoro analogue of zeatin itself. Another series of zeatin derivatives in which the methyl group was replaced by alkyl (ethyl, p ropyl, and isopropyl), phenyl, and benzyl groups were also obtained. T he ethyl analogue was found to be more active than zeatin, while the o thers were inactive or slightly active.