A New Synthesis of the Sex Pheromone of the Indian Meal Moth Plodia Interpunctella hb. (Lepidoptera, Pyralidae)

New synthesis of (9Z,12E)-9,12-tetradecadien-1-yl acetate, the sex pheromone of the indian meal moth Plodia interpunctella (Lepidoptera, Pyralidae), were developed. The synthesis was based on a C8+C2=C10 and C10+C4=C14 coupling scheme. The route involves, as the key step, the use of the mercury derivative of the terminal-alkyne -functionalised as intermediate.The first coupling reaction took place between 1-tert-butoxy-8-bromo-octane and lithium acetylide-ethylendiamine complex obtaining 1-tert-butoxy-dec-9-yne, which is transformed in di[tert-butoxy-dec-9-yne]mercury.In the second coupling reaction, the mercury derivative was directly lithiated and then alkylated with (E)-1-bromo-2-butene obtaining 1-tert-butoxy-(9-yne,12E)-9,12-tetradecaenyne. After stereoselective reduction in the presence of NiP-2 catalyst and acetylation gave (9Z,12E)-9,12-tetradecadien-1-yl acetate with 82% isomeric purity.

The Use of Mercury Compounds in the Synthesis of Some Lepidoptera Insect Sex Pheromones with Monoenic Structure

New and practical synthesis of (E)-11-tetradecen-1-yl acetate and (Z)-11-hexadecen-1-yl acetate were developed. The synthesis were based on a C12+C2=C14 and C12+C4=C16 coupling scheme. The routes involve, as the key step, the use of the same mercury derivative of the terminal-alkyne w-functionalised as intermediate.The first coupling reaction was effected by adding 1-tert-butoxy-10-bromodecane to monosodate acetylene, obtained in situ from DMSO and sodium hydride. It was prepared 1-tert-butoxy-dodec-11-yne, which is transformed in di[tert-butoxy-dodec-11-yne]mercury, the common intermediate in the synthesis of the two pheromones. In order to obtain (E)-11-tetradecen-1-yl acetate, the mercury derivative was directly lithiated and then alkylated with 1-bromoethane obtaining 1-tert-butoxy-tetradec-11-yne. After reduction with lithium aluminium hydride of 1-tert-butoxy-tetradec-11-yne and acetylation gave (E)-11-tetradecen-1-yl acetate with 99 % isomeric purity. In order to obtain (Z)-11-hexadecen-1-yl acetate, the mercury derivative was directly lithiated and then alkylated with 1-bromobutane obtaining 1-tert-butoxy-hexadec-11-yne. After acetylation of 1-tert-butoxy-hexadec-11-yne and stereoselective reduction in the presence of NiP-2 catalyst gave (Z)-11-hexadecen-1-yl acetate with 90 % isomeric purity.

Convenient Synthesis of (Z)-7- and (E)-9-dodecene-1-yl Acetate, Components of Some Lepidoptera Insect Sex Pheromone

Were developed new and practical synthesis of (Z)-7-dodecene-1-yl acetate and (E)-9-dodecene-1-yl acetate. The routes involve, as the key step, the use of the mercury derivative of the terminal-alkyne w-functionalised as intermediate. The synthesis of (Z)-7-dodecene-1-yl acetate was based on a C6+C2=C8 and C8+C4=C12 coupling scheme, starting from 1,6-hexane-diol. The first coupling reaction took place between 1-tert-butoxy-6-bromo-hexane and lithium acetylide-ethylendiamine complex obtaining 1-tert-butoxy-oct-7-yne, which is transformed in di[tert-butoxy-oct-7-yne]mercury. The mercury derivative was directly lithiated and then alkylated with 1-bromobutane obtaining 1-tert-butoxy-dodec-7-yne. After acetylation and reduction with lithium aluminium hydride of 7-dodecyne-1-yl acetate gave (Z)-7-dodecene-1-yl acetate with 96 % purity. The synthesis of (E)-9-dodecene-1-yl acetate was based on a C8+C2=C10 and C10+C2=C12 coupling scheme, starting from 1,8-octane-diol. The first coupling reaction took place between 1-tert-butoxy-8-bromo-octane and lithium acetylide-ethylendiamine complex obtaining 1-tert-butoxy-dec-9-yne, which is transformed in di[tert-butoxy-dec-9-yne]mercury. The mercury derivative was directly lithiated and then alkylated with 1-bromoethane obtaining 1-tert-butoxy-dodec-9-yne. After reduction with lithium aluminium hydride of 1-tert-butoxy-(E)-9-dodecene and acetylation was obtained (E)-9-dodecene-1-yl acetate with 97 % purity.

A Practical Synthesis of (Z)- and (E)-8-Dodecene-1-yl Acetate, Components of Lepidoptera Insect Sex Pheromones

New and practical synthesis of (Z)-8-dodecene-1-yl acetate and (E)-8-dodecene-1-yl acetate were developed. The synthesis were based on a C3+C6=C9 and C9+C3=C12 coupling scheme, the starting material being 2-propyn-1-ol and 1,6-hexandiol. The routes involve, as the key step, the use of the same mercury derivative of the terminal-alkyne w-functionalised as intermediate. The first coupling reaction took place between methoxyallene and Grignard reagent of 1-tert-butoxy-6-bromo-hexan obtaining 1-tert-butoxy-non-8-yne, which is transformed in di[1-tert-butoxy-non-8-yne]mercury, the common intermediate in the synthesis of the two pheromones. In order to obtain (Z)-8-dodecene-1-yl acetate and (E)-8-dodecene-1-yl acetate, the mercury derivative was directly lithiated and then alkylated with 1-bromo-propan obtaining 1-tert-butoxy-dodec-8-yne. After acetylation of 1-tert-butoxy-dodec-8-yne and stereoselective reduction in the presence of NiP-2 catalyst gave (Z)-8-dodecene-1-yl acetate with 85 % isomeric purity. After reduction with lithium aluminium hydride of 1-tert-butoxy-dodec-8-yne and acetylation was obtained (E)-8-dodecene-1-yl acetate with 90% isomeric purity.

Crystal structure ofN1-benzyl-N1,N2,N2-trimethylethane-1,2-diaminium dichloride

In the title molecular salt, C12H22N22+·2Cl−, which was obtained as a by-product in the attempted synthesis of a mercury derivative, the conformation of the N—C—C—N bond in the cation isanti[torsion angle = 175.1 (10)°]. In the crystal, the cations are linked to the anions by N—H...Cl hydrogen bonds, generating ion-triplets. These are linked by numerous weak C—H...Cl interactions, generating a three-dimensional network. The structure was refined as an inversion twin.

Crystallization of the C-terminal domain of the bacteriophage T7 fibre protein gp17

Bacteriophage T7 attaches to its host using the C-terminal domains of its six fibres, which are trimers of the gp17 protein. A C-terminal fragment of gp17 consisting of amino acids 371–553 has been expressed, purified and crystallized. Crystals of two forms were obtained, belonging to space groupP212121(unit-cell parametersa= 61.2,b= 86.0,c= 118.4 Å) and space groupC2221(unit-cell parametersa= 68.3,b= 145.6,c= 172.1 Å). They diffracted to 1.9 and 2.0 Å resolution, respectively. Both crystals are expected to contain one trimer in the asymmetric unit. Multiwavelength anomalous dispersion phasing with a mercury derivative is in progress.

Crystallization and preliminary X-ray studies of sialidase L from the leech Macrobdella decora

Functional monomeric 83 kDa sialidase L, a NeuAcα2→3Gal-specific sialidase from Macrobdella leech, was expressed in Escherichia coli and readily crystallized by a macroseeding technique. The crystal belongs to space group P1 with unit-cell parameters a = 46.4, b = 69.3, c = 72.5 Å, α = 113.5, β = 95.4 and γ = 107.3°. There is one molecule per unit cell, giving a Vm = 2.4 Å3 Da−1 and a solvent content of 40%. Native and mercury-derivative data sets were collected to 2.0 Å resolution. Threading and molecular-replacement calculations confirmed the existence of a bacterial sialidase-like domain.