(+)-Methyl 11-Fluorojasmonate as a Designed Antimetabolite of Methyl Jasmonate: Synthesis and Plant Growth Regulatory Activity

INTRODUCTION Jasmonoids have been found to play important roles in plant growth regulation.1 Recent development of industrial production of ()-methyl jasmonate (MJA, 1) from Nippon Zeon Co., Ltd. made it possible to use MJA as a practical plant growth regulator.2 we have been studying new jasmonoid analogs to develop more active compounds.3 we took notice of the hypothesis that the metabolic inactivation pathway of MJA begins with hydroxylation at 11or 12position (11:12=ca.9/1). This hypothesis was supported by the metabolic experimental result of [2-14C]-9, 10-dihydrojasmonic acid.4 Furthermore, methyl 11-hydroxy(11-OHMJA, 2)5 and 12-hydroxyjasmonates (12-OH-MJA, 3)6) were reported to be inactive for some plant growth inhibition tests.8 So we supposed that blocking at 11-position would increase the plant hormonal activities of MJA. Previously, we reported that the growth inhibitory activity on rice seedlings of methyl 12, 12, 12-trifluorojasmonate (12-F3-MJA, 4), which was designed for antimetabolite for 12-hydroxylation, was stronger than that of MJA.3a) Continuing this study, we designed 11-fluoro analog of MJA (11-F-MJA, 5) as antimetabolite for 11-position. Substitution by one fluorine atom would also repress the stereochemical change around this position. In this paper, synthesis and some plant growth regulatory activities of 5 are described.