Scolytus

Sn2 Reactions with epoxides and aziridines are also synthetically useful. An example of epoxide cleavage with an organocopper reagent with sp carbon moieties is the enantioselective synthesis of (3S, 4S)-4-methyl-3-heptanol (53), an elm bark beetle (Scolytus multistriatus) pheromone [42]. The chiral epoxy oxazolidine 51 [43], prepared from (R)-phenylglycinol, reacted with a propylmagnesium bromide-derived cuprate at —70 °C to afford the oxazolidine 52 in 74% yield (Scheme 9.12). Compound 52 was converted into the target molecular 53 by conventional procedures. 

Almond bark beetle, Scolytus amygladi (Coleoptera Scolytidae) ... 

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). 

Magnoline Inhibited feeding of bark beetle (Scolytus multistriatus) 439... 

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... 

Blight M. M., Wadhams L. J. and Wenham M. J. (1978) Volatiles associated with unmated Scolytus scolytus beetles on English elm differential production of a-multistriatin and 4-methyl-3-heptanol, and their activities in a laboratory bioassay. Insect Biochem. 8, 135-142. 

Blight M. M., Henderson N. C. and Wadhams L. J. (1983) The identification of 4-methyl-3-heptanone from Scolytus scolytus (F.) and Scolytus multistriatus (Marsham). Absolute configuration, laboratory bioassay and electrophysiological studies on S. scolytus. Insect Biochem. 13, 27-38. 

Elliot W. J., Hromnak G., Fried J. and Lanier G. N. (1979) Synthesis of multistriatin enantiomers and their actions on Scolytus multistriatus (Coleoptera Scolytidae). J. Chem. Ecol. 5, 279-287. 

Gerken B., Grtine S., Vite J. P. and Mori K. (1978) Response of European populations of Scolytus multistriatus to isomers of multistriatin. Naturwissenschaften 65, 110-111. 

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. 

S, 4S)-4-Methylheptan-3-ol is a component of the aggregation pheromone of the elm bark beetle Scolytus multistriatus. It is readily synthesized from the (s) pinanediol ester of propylboronic acid as shown in Figure B6.2. 

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. 

Such a sequence has been successfully used115 for the synthesis of 4-methyl-3-heptanol, the major constituent of the aggregation pheromone of the elm bark beetle (Scolytus multistriatus Marsham)117 and zir-butyM-methyltetrahydro-2-furanone118 known as quercus lactone or oak lactone. ... 

Application of the preceding strategy to multistriatin synthesis (Scheme 11.26) started with compound 7, which was deoxygenated at C3 and further elaborated to ketone 106 [49]. Wittig methylenation provided 107, and subsequent double bond reduction using Wilkinson s catalyst afforded the dimethylated compound 34 [93]. Further manipulation yielded a-multistriatin 108, the pheromone of Scolytus multistriatus. Other syntheses of this pheromon from sugars have been reported [48,94,95]. 

Scolytus rugulosus. See Shothole borers Scorch, leaf. See Leaf scorch Scurf... 

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