Synthesen von trail‐Pheromonen der Pharaoameise (Monomorium pharaonis(L.))

Syntheses of trail Pheromones of the Pharao Ant (Monomorium pharaonis (L.)) Hofmann‐Löffler‐reaction, starting from 5‐amino‐tridecane yields pyrrolidine mixtures containing 2‐butyl‐5‐pentyl‐pyrrolidine 1, known as a trail pheromone of the Pharao ant. An analogous reaction of 7‐amino‐pentadecane leads to 2‐hexyl‐5‐pentyl‐pyrrolidine 2 as a mixture with an isomer. Definite 2,5‐dialkyl‐pyrrolidines are obtained by Seebach alkylation from N‐nitroso‐pyrrolidines e.g. 1, 2 or 3, the latter with an unsaturated side chain. Change of reaction conditions led to 2,2‐dialkyl‐pyrrolidines. Dehydrogenation followed by hydrogenation converts a mixture of cis‐trans‐isomers of 1 into definite cis‐compound 1a. Trails of these pyrrolidines are followed by Pharao ants.