The Fungicidal Benzothiazole Methoxyacrylates: Synthesis, Conformational Analysis and Fungicidal Activity

Synthesis of a series of novel benzothiazole methoxyacrylate compounds (3-4) based on the antifungal natural product, Strobilurin A is described.Fungicidal activities of 3-4 against six representative fungal diseases and their comparative conformational analyses vs Strobilurin A are accounted.Strobilurins (1) and oudemansins (2) are antifungal metabolites which have been produced by various fungi such as Strobilurus and Oudenmansiella (Figure1). 1 Me MeO CO 2 Me Strobilurin A, 1a Strobilurin B, 1b Cl OMe MeO CO 2 Me Oudemansin A, 2a Me OMe Me MeO CO 2 Me a b c d MeO CO 2 Me Oudemansin B, 2b Me OMe OMe Cl Figiure 1. Natural fungicidal MOA compounds: strobilurins and oudemansins.They show a potent fungicidal activity with a broad spectrum and inhibit mitochondrial respiration by blocking electron transport at the cytochrome bc 1 complex. 2The following efforts by major industrial R & D groups to develop more active synthetic analogs have led to a new class of fungicides containing methyl β-methoxyacrylate (MOA) group. 3Azoxystrobin by Zeneca Agrochemicals 3b and Kresoxim-methyl by BASF 3c are the first two MOA compounds recently introduced to the market (Figure 2).