Pheromones from pharaoh ants

From the above survey of results the synthetic potential of the oxazinolactam intermediate 46 in hand, we envisaged to synthesize monomorine I (62) which constitutes of an extension of the methodology based on intramolecular nitroso Diels-Alder cycloaddition. The relative stereochemistry of this substance, isolated as one of the trail pheromones from Pharaoh ants (Monomorium pharaonis L.) (ref. 19), has been determined its relative stereochemistry by nonstereoselective synthesis (ref. 20). More recently, a stereospecific synthesis of racemic 62 (ref. 21) and a chiral synthesis of the (-)-enantiomer of natural 62 (ref. 22) were reported. 

A trail pheromone of the Pharaoh ant was identified as 3-butyl-5-methylindolizidine of the stereochemistry given in (219) (75JHC289). Slaframine (220) is a metabolite isolated from Rhizoctonia leguminicola responsible for producing excessive salivation in cattle. A stereoselective synthesis was reported (73JOC3848). Swainsonine (221), a potent inhibitor of a-mannosidase, has been isolated from Swainsona caneszens. The stereochemistry was derived from the NMR spectrum (79AJC2257). 

Carbon-13 n.m.r. assignments have been reported for a number of isomeric 3-butyl-5-methyloctahydroindolizines that were synthesized in studies of the trial pheromone of the Pharaoh ant, and for some closely related indolizidines. This work includes a detailed discussion of the preferred conformations of these compounds.15 Securinegine, a minor alkaloid from Securinega suffruticosa Rehd., is isomeric with securinine, and the structure (22) has been proposed.16... 

We end with an example that includes methods from this chapter as well as some revision and a reminder of stereochemistry. Monomorine I 71 is the trail pheromone of Pharaoh s ant (Monomorium pharaonis). These ants are pests in hospitals as they spread infections and they follow a trail of monomorine as they go about their evil work. Synthetic monomorine might be... 

Certain 2,5-dialkyl-pyrrolidines, which are trail pheromones of the pharaoh ant (Monomorium pharaonis L.), have been synthesized by application of the Hofmann-Loffler reaction to 5-aminotridecane and 7-aminopentadecane. The same type of compound results from Seebach alkylation of TV-nitrosopyrrolidines.4... 

All the currently known indolizidine and quinolizidine alkaloids isolated from ants are illustrated in Fig. 6. (+ )-Monomorine I (427), the well-studied trail pheromone constituent of the Pharaoh ant Monomorium pharaonis), and the analogs 428-431 were described in the earlier volumes in this series. These five compounds are 3,5-disubstituted indolizidines bearing short saturated or mono-unsaturated hydrocarbon chains. The relative stereochemistry in monomorine VI (430) still remains unknown, while that of 431 was atypical for the class at the time of its isolation 380). The structural resemblance of fiiis group of alkaloids to the... 

The octahydroindolizine trail pheromone (412) of the Pharaoh ant (Monomorium pharaonis) was first prepared by Ritter et al. (181) as a mixture of stereoisomers, beginning with a termolecular condensation (Scheme 74). Oliver and Sonnet (182) then unambiguously synthesized the four stereoisomers from 2,6-lutidine (413) (Scheme 75) and 2-butyl-pyrrole (418) (Scheme 76). 

Mori reported an improved synthesis of (3S,4P,6 ,10Z)-faranal (37), the trail pheromone of the Pharaoh s ant (Monomorium pharaonis) [84]. As summarized in Scheme 55, the key-reaction was the coupling of iododiene A with iodide E. The geometrically pure A was prepared by the zirconocene-mediated carbo-alumination reaction, and E was prepared from B by the asymmetric cleavage of its epoxy ring to give C (77% ee), which could be purified via its crystalline 3,5-dinitrobenzoate D. 

A few years ago the complete structure of periplanone-B, apart from its stereochemistry, was elucidated and published by our research team (32,33,34) with Persoons as the principal investigator, who included this work in his doctoral thesis (35), and shared the Royal Dutch Shell Prize for 1978 with Ritter for this work and the structure elucidation of faranal, the trail pheromone of the Pharaoh s ant, Monomorium pharaonis (36,37). 

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