Design and synthesis of Strigolactones using keteneiminiums as key intermediates:potential application to Crop Enhancement and Crop Protection

Strigolactones are the last discovered phytohormones. Among the numerous roles that strigolactones play in plant growth and development, they have been shown to control the root and shoot architecture, having significant consequences on plant adaptation to environmental conditions and abiotic stress. In addition, strigolactones signaling might influence the harvest yield of field crops.

We describe the stereoselective synthesis of natural strigolactones as well as of their derivatives displaying improved biological performance using keteneiminium salts as key intermediates. We disclose also the synthesis of non-canonical strigolactones as methyl carlactonoate, carlactonic acid and heliolactone. In addition, we illustrate the use of keteneiminiums intermediates in other Crop Protection projects leading to small rings derivatives as well as to aromatic compounds.

Alain De Mesmaeker, Syngenta Crop Protection, Research Chemistry, CH-4332 Stein, Switzerland - CV