The present invention relates to a plant protective composition comprising α-hydroxy-acid or a derivative thereof. The present invention further relates to a method of protecting plants from biotrophic pathogens comprising contacting the plants with the plant protective composition.
Transformation of 5-Hydroxy- to (5-Chloropentanoyl)amino Derivatives under ‘Direct Amide Cyclization’ Conditions
The application of the ‘directamidecyclization’ conditions to the linear δ-hydroxy diamide 11 is described (Scheme 3). Instead of the cyclization to the expected nine-membered cyclodepsipeptide, only the chloro acid 12 was obtained. Its formation could be explained by consecutive formation of the 1,3-oxazol-5(4H)-one 16 and the six-membered imino lactone 17 as intermediates (Scheme 4). The spontaneous