Abstract
The queen substance [(E) -9-oxo-2-decenoic acid] 1 is a pheromone secreted by the queen honeybee (Apis mellifera) and inhibits ovary development in worker bees and queen rearing within the colony. In consideration of its biological importance, various routes for its synthesis have been published. The synthesis of 1 from methyl 3-formylpropionate 2 is reported here for the first time.
Keto-ester 4, prepared from 2 and 2-methyl-2-vinyl-1, 3-dioxolane 3 by radical addition reaction in 76% yield, was treated with hydrazine monohydrate in the presence of potassium hydroxide in diethylene glycol to give ethylenedioxy carboxylic acid 5 in 68% yield. The reduction of 5 with sodium bis (2-methoxyethoxy) aluminum hydride in benzene under reflux gave acetal alcohol 6 in 75% yield, which was then oxidized to acetal aldehyde 7 with pyridinium chlorochromate in 76% yield. Acetal aldehyde 7 was condenced with malonic acid to give 8 in 71% yield. The hydrolysis of 8 was carried out with 1 M hydrochloric acid to give 1 in 92% yield.
