Leiobunum vittatum

The (R)- and (S)-enantiomers of (E)-4.6-dimethyl-6-octene-3-one (147), a defense substance of spiders (known commonly as daddy longlegs Leiobunum vittatum and L. calcar) were recently synthesized by Enders and Baus 163> using the (R)-proline derivative RAMP and the (S)-proline derivative SAMP (137) as chiral auxiliary, respectively. (S)- and (R)-enantiomers of (147) have been obtained in an overall chemical yield of 70% and in very high stereoselectivities of 95% e.e., respectively. 

Enders, D., Baus, U. Asymmetric synthesis of both enantiomers of (E)-4,6-dimethyl-6-octen-3-one, the defensive substance of daddy longlegs, Leiobunum vittatum and L. calcar (Opiliones). Liebigs Ann. Chem. 1983, 1439-1445. 

Clawson RC. Morphology of defense glands of the opilionids (daddy longlegs) Leiobunum vittatum and Leiobunum flavum (Arachnida, Opiliones, Palpatores, Phalan-giidae). J Morphol 1988 196(3) 363-81. 

Enders synthesises this simple compound, the defence secretion of the daddy longlegs insect, Leiobunum vittatum and L. calcar, to illustrate the use of his RAMP and SAMP chiral auxiliaries (see section 5.3.2). The imine of 3-pentanone and SAMP is deprotonated with LDA, and the anion alkylated with -l-bromo-2-methylbut-2-... 

In a similar manner, the alicyclic precursor of multistriatin may be 4,6-dimethyl-7-octen-3-one (301, Scheme 55). Similar compounds have been obtained in alarm and defensive secretions of certain insects. Pales et al. (451) found that the mandibular gland secretion of the ant Manica mutica contained mainly 4,6-dimethyl-4-octen-3-one. Meinwald et al. (452) identified 4,6-dimethyl-6-octen-3-one in the defensive secretion of the daddy long legs, Leiobunum vittatum. 

Meinwald, J., A. F. Kluge, J. F. Carrel, and T. Eisner Acyclic ketones in the defensive secretion of a daddy long legs (Leiobunum vittatum). Proc. Natl. Acad. Sci. USA 68,1467—1468 (1971). 

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See also in sourсe #XX -- [ ]

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