Bark beetle, European elm

Claisen rearrangement of glycolates. Two laboratories 2 have reported that allylic glycolate esters undergo Claisen-Ireland rearrangement (6, 276-277) with useful diastereoselectivity. This rearrangement was used in a synthesis of 1, the aggregation pheromone of the European elm bark beetle.1... 

Often related insect species are not all sensitive to a particular allomone. For example, juglone is a feeding deterrent to the smaller European elm bark beetle (Scolytus multistriatus) but not to the closely related hickory bark beetle (Scolytus quadrispinosus) (106,107). 

Stereoselective reactions with aldehydes. The related (E)-2-pentenyltin reagent 2 also reacts with aldehydes to form predominantly erythro adducts such as 3. This reaction was used for a stereoselective synthesis of an aggregation pheromone (4) of the European elm bark beetle.1... 

B) Western balsam bark beetle, Dryocoetes confusus formation of endo-brevicomin [(1 F ,5S,7S)-7-ethyl-5-methyl-6,8-dioxabicyclo[3.2.1 ]octane] from ( )-6-nonen-2-one (Vanderwel et a/., 1992a) (C) Spruce beetle, Dendroctonus rufipennis formation of frontalin [(1S, 5fl)-(-)-1,5-dimethyl-6,8-dioxabicyclo[3.2.1]octane] from 6-methyl-6-hepten-2-one (Perez ef a/., 1996 Francke etai, 1995 Francke and Schulz, 1999) (D) European elm bark beetle, Scolytus multistriatus hypothetical formation of oc-multistriatin [(1 S,2F ,4S,5F )-(-)-2,4-dimethyl-5-ethyl-6,8-dioxabicyclo[3.2.1]octane] from 4,6-dimethyl-7-octen-3-one (Francke and Schulz, 1999) and E The colored... 

Birch M. C., Paine T. D. and Miller J. C. (1981) Effectiveness of pheromone masstrapping of the smaller European elm bark beetle. California Agriculture 35, 6-7. 

Gore W. E., Pearce G. T., Lanier G. N., Simeone J. B., Silverstein R. M., Peacock J. W. and Cuthbert R.A. (1977) Aggregation attractant of the European elm bark beetle, Scolytus multistriatus, production of individual components and related aggregation behavior. J. Chem. Ecol. 3, 429 446. 

Mori K. (1974) Synthesis of (15 2R 45 55)-(-)-a-multistnatin the pheromone in the smaller European elm bark beetle, Scolytus multistriatus. Tetrahedron 32, 1979-1981. 

The terpenoid-exocrine theme emphasized by scolytid beetles was again evident when the chemical constitution of the secondary attractant for the smaller European elm bark beetle, Scolytus multistriatus, was elucidated. The aggregation pheromone was identified as a mixture of (-)-4-methyl-3-heptanol, 2,4-dimethyl-5-ethyl-6,8-dioxabicyclo [3.2.1]octane (multistriatin) (XXII), and (-)-a-cubebene (XXIII), a host-derived synergist (70). All three compounds are required for the maximum attraction of beetles. The inactive diastereomers of 4-methyl-3-heptanol and multistriatin did not inhibit the responses of airborne beetles. 

Eggplant, 93-94 European elm bark beetles, 288 Flatheaded borers... 

Synthesis of those insect aggregation pheromones having bridged structures may have important economic consequences. Multistriatin (120) is an aggregation pheromone of a European elm bark beetle. A stereoselective synthesis "" has been reported from tartaric acid. A delightfully simple synthesis " of frontalin (121), a pheromone of the pine beetle, is by photolysis of heptane-2,6-dione in methanol-titanium chloride. We also note further photochemical studies... 

Pearce, G.T., W.E. Gore, R.M. Silverstein, J.W. Peacock, R.A. Cuthbert, G.N. Lanier, and J.W. Simeone Chemical Attractants for the Smaller European Elm Bark Beetle Scolytus multistriatus (Coleoptera Scolytidae). J. Chem. Ecol. 1,115-124 (1975). 

S,4S)-4-Methylheptan-3-ol (41)(glucose numbering), a pheromone component of the smaller European elm bark beetle, has been prepared conventionally from D-glucose via the 3-deoxy-3-C-methyl-altroside (42) as outlined in Scheme 13, utilizing an oxidation-reduction sequence to effect double epimerization at C-2 and C-3, and Wittig reactions to lengthen the chain appropriately. 

The response of the European elm bark beetle to isomers of its pheromone blend was determined with two separate laboratory bioassays and field tests (93, 318). A combination of 3 compounds that act syner-gistically was found (-)-4-methyl-3-heptanol (294a), (-)-a-multistriatin (303a), and (—)-a-cubebene (283) (for formulas, see pp. 48, 49) (93). The absolute configuration of the (—)-a-multistriatin is IS,2R,4S,5R (49) and that of the (—)-4-methyl-3-heptanolis 38,48(147). Both the texam alarm pheromone, (5)-(+)-methyl-3-heptanone, and the alcohol above share 45 stereochemistry. Of interest is the fact that the reduction of decalones by microbial enzymes is usually stereoselective, with optically active alcohols of 5-configurations being obtained (319). 

Another company (624, 625) supplies a controlled release dispenser, which is a three-layer plastic laminated sheet consisting of a bottom protective layer, a middle pheromone reservoir layer, and a top permeable layer through which the pheromone diffuses. The sheet can be cut into ribbons and applied over an area. Formulations have been field tested on a number of insect pests gypsy moth, pink bollworm, peachtree borer, lesser peach tree borer, soybean looper, cabbage looper, European elm bark beetle, tobacco budworm, fall armyworm, tussock moth, eastern spruce budworm, and Mediterranean fruit fly. 

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