Endo-brevicomin

Salom SM, Billings RE, Upton WW, Dalusky MJ, Grosman DM, Payne TI, Berisford GW, Shaver TN, Effect of verbenone enantiomers and racemic endo-brevicomin on response of Dendroctonus frontalis (Coleoptera Scolitidae) to attractant-baited traps, Can JForRes22 S2 i—3 i, 1992. 

Padwa synthesized the oxo-brevicomin analogue 174 in 60% yield as a 2 1 mixture of the exo and endo isomers. Dithioacetalization followed by Raney Ni reduction of the dithioketal produced the exo- (175) and endo-brevicomin in good... 

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... 

Ryker L. C. and Rudinsky J. A. (1982) Field bioassay of exo- and endo-brevicomin with Dendroctonus ponderosae in lodgepole pine. J. Chem. Ecol. 8, 701-707. 

Schurig V., Weber R. A., Nicholsen G. J., Oehlschlager A. C., Pierce H. D., Jr, Borden J. H. and Ryker L. C. (1983) Enantiomer composition of natural exo- and endo-brevicomin by complexation gas chromatography/selected ion mass spectrometry. Naturwissenschaften 70, 92-93. 

The emerging Mo-catalyzed ARCM technology summarized above has been utilized in a brief and enantioselective total synthesis of endo-brevicomin (30) by Burke. The key step, as illustrated in Scheme 7, is the desymmetrization of achiral triene 28 [17],... 

The addition of diorganozinc reagents to a-alkoxyaldehydes furnishes selectively protected 1,2-diols.19 Applications toward the synthesis of pheromones like (-)-exo- and (-)-endo-brevicomin 2 and 3 exploits the catalytic nature of the stereochemical induction, e.g. the newly formed chiral centre depends only on the configuration of the chiral catalyst 1. 

H. Redlich, W. Bruns, W. Francke, V. Schurig, T. L. Payne, and J. P. Vit6, Chiral building units from carbohydrates. XIII. Identification of the absolute configuration of endo-brevicomin from Dendroctonus frontalis and synthesis of both enantiomers from D-ribose, Tetrahedron 43 2029 (1987). 

Both exo- and endo-brevicomin vide infra), in optically active form, have been synthesized by elaboration of a-alkoxy aldehyde (201). Condensation of the 1-trimethylsilylvinylcopper reagent (198) with the ( )-glyceraldehyde derivative (199) gave syn product (200) in >85% yield with over 98% dia-stereoselectivity (Scheme 36). Hydroxy protection, hydrolysis and periodate cleavage of the vtc-diol converted (200) to aldehyde (201) in 50-65% overall yields for the two steps. 

On elaboration of l,5-hexadiene-3,4-diol through a 1,3-dioxolane derivative, the RCM delivers a precursor of either exo-brevicomin or endo-brevicomin. A route to (+)-malyngolide also exploits the RCM process. A successful cyclization-fragmentation approach to medium-sized rings is based on the RCM reaction of 2-hydroxycycloalkanones that are substituted with proper alkenyl groups at both a- and a -positions.- ... 

Recently in 2005, we synthesized 10 g of (+)-endo-brevicomin, the minor component of the pheromone of the male southern pine beetle, Dmdroctonus frontalis [22-24]. We used lipase AK in this synthesis to desymmetrize the prochiral diol. Dr. B. T. Sullivan at the U.S. Forest Service is currently studying the practicality of the pheromone traps with a mixture of (+)-endo-brevicomin, frontaKn and a-pinene. 

An alternative consists of acylation with NdSl-dimethylamides and a subsequent diastereoselective reduction [17]. The sequence was applied in the enantioselective total synthesis of (-i-)-endo-brevicomin 33 [Eq. (11)] [21]. 

When MBH adducts 169 are heated in a high-boiling aromatic hydrocarbon, they undergo an intermolecular dehydrative double cyclization to produce functionalized 6,8-dioxabicyclo[3.2.1]octanes 171 (Scheme 3.68), which are often present as the basic framework in several pheromones, e.g. frontalin, exo-and endo-brevicomins, ot-multistriatin, However, the stereoselectivity in... 

An illustrative example for the strength of this methodology was reported by Kim et al. who used an enamine-catalyzed a-oxidation in the synthesis of the bark beetle pheromones (+)-exo- and (-)-enrfo-brevicomin (124) (111). The asymmetric proline-catalyzed a-hydroxylation of butyraldehyde (125) with 123 gave the crude anilinooxy compound 126 in excellent enantioselectivity (>98%). Compound 126 was used directly further to give (+)-exo- and (-)-endo-brevicomin (124) in just three more steps (Scheme 29) (111). 

Scheme 29 Proline (12)-catalyzed a-oxygenation in the synthesis of (+) -exo- and (—)-endo-brevicomin (124)...

Kim SG, Park TH, Kim BJ (2006) Efficient Total Synthesis of (+)-Exo-, (-)-Endo-Brevicomin and Their Derivatives via Asymmetric Organocatalysis and Olefin Cross-Metathesis. Tetrahedron Lett 47 6369... 

Both enantiomers of endo-brevicomin have been synthesized from the D-ribose derivative (69), prepared from the sugar in 4 steps, by appropriate manipulation of the two ends of the chain the (+)-... 

As an alternative to baker s yeast, the use of plant tissues (e.g., from apple, carrot, cucumber, onion, or potato) has been suggested [112,113]. It remains unclear, however, whether endophytic microorganisms are involved in these reductions [114]. Heterocyclic ketones [111, 115-117] as well as many a-hydroxy ketones [96,118-121] have been the subject of yeast-mediated reductions. For the latter compounds very high ee values have been obtained, albeit the yields were moderate. Monobenylated (S)-l,n-diols have been prepared using highly diluted yeast suspensions, and ee values up to 95% could be achieved [122]. Yeast-mediated reductions of acyclic ketones were key steps in the total synthesis of the pheromone sulcatol [123], brefeldin A [124], and endo-brevicomin [125]. 

Erythritol-derived diol 8 was acetylated with vinyl acetate and lipase AK (Amano) to give (2S,3R)-9 (Figure 24.5) [8]. This half-acetate 9 was converted to (+)-endo-brevicomin, a male-produced component of the southern pine beetle pheromone. 

Preparation of half-acetate (2S, 3/ )-9, which was converted to (+)-endo-brevicomin. 

Wasserman and Barber (123) observed that heating the ketoepoxides (184 a and 184 b) in a sealed tube stereospecifically gave exo- and endo-brevicomin, respectively (Scheme 35). A similar synthesis of the endo-epimer has been reported by Look (124). Acetylenic ketone (157) was prepared by Coke et al. (125) after treatment of chloride (186) with methyl lithium and thermal cleavage of the resultant intermediate (Scheme 36). Catalytic reduction to the E olefinic ketone (162 a) was followed by epoxidation and thermolysis to give exo-brevicomin. Rodin et al. (126) obtained cxo-brevicomin from acid catalyzed cyclization of ketoepoxide (184a). 

So far, enantioselective olefin metathesis has the largest impact on organic synthesis in the desymmetrization of achiral polyenes [81] an illustrative example refers to the total synthesis of endo-brevicomin [82]. The catalytic asymmetric cycli-zation of achiral trienes and meso-tetraenes via ARCM proceeds in excellent enan-tioselection (e.e. > 99 %) as demonstrated for dihydrofuran 163 (Scheme 11.40). 

A similar approach was recently reported for the synthesis of ( )-Frontalin, ( )-endo-Brevicomin, and (—)-exo-Brevicomin [154]. 

Lee H-Y, Jung Y, Moon H (2009) A facile total synthesis of (—)-Frontalin, (-)-endo-brevicomin and (-)-exo-brevicomin through PtCLi catalyzed hydroalkoxylation reaction. Bull Korean Chem Soc 30 771-772... 

Finally, an elegant synthesis of brefeldin A started from 71 to afford (S)-72 with 99% e.e. [106], and a kinetic resolution by BY has been used for the synthesis of endo-brevicomin [107,108] (Fig. 21). Thus, reduction of racemic 75 under anaerobic conditions afforded via 76 a mixture of endo-11 (corresponds to a syn-selective reduction) and exo-78 [107]. 

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