Triterpenoid total synthesis. Part 2. Synthesis of glycinoeclepin A, a potent hatching stimulus for the soybean cyst nematode
Abstract
Glycinoeclepin A, a natural hatching stimulus for the soybean cyst nematode, was enantioselectively synthesized starting from two chiral building blocks, both of which were obtained by reduction of prochiral 1,3-diketones with baker's yeast. The key reactions are aldol condensation to introduce asymmetry at C-12 and -13 and reductive lactone cleavage followed by aldol-type condensation for c-ring formation.