Parallel solution-phase synthesis of substituted 2-(1,2,4-triazol-3-yl)benzimidazoles

A solution-phase synthesis for the preparation of substituted 2-(1,2,4-triazol-3-yl)benzimidazoles from triazole aldehydes and ortho-phenylenediamines has been developed for the purpose of producing diverse lead generation libraries. Crude products were obtained and further purified by mass-guided preparative HPLC.     

Photocatalytic lithography with image inversion

The feasibility of the inversion of metal images obtained by the chemical deposition of nickel onto Pd²⁺-loaded films of nanostructural TiO₂ exposed to high irradiation doses has been demonstrated. This permits the generation of both negative and positive metallic pictures by varying the irradiation dose, which expands the scope for obtaining planar metallic elements with complex structural organization. Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 45, No. 1, pp. 32–35, January–February, 2009.     

Kinetics of structural relaxation of bulk and ribbon Pd<Subscript>40</Subscript>Cu<Subscript>30</Subscript>Ni<Subscript>10</Subscript>P<Subscript>20</Subscript> glasses determined from electrical resistance measurements

The electrical resistances of ribbon and bulk Pd₄₀Cu₃₀Ni₁₀P₂₀ metallic glasses, whose quenching rates differ by four orders of magnitude, were precisely measured during cyclic heating. Three stages of electrical resistance relaxation are detected as the maximum heating temperature increases. The first and third stages decrease the electrical resistance, and the second stage increases it. The first stage is shown to be caused by the relaxation of deformation-induced internal stresses and not to be related to the excess free volume concentration, which differs by a factor of about 2 in the ribbon and bulk samples. The second stage reflects structural relaxation in the glass and is only partly related to its free volume. The third relaxation stage is assumed to be caused by fine precrystallization phenomena like phase separation. The effect of deformation by rolling or quenching from the temperature range of a supercooled melt on the resistance relaxation kinetics was also studied.     

Synthesis of Methyl-3-desoxy-3-C-methyl-4-O-benzyl-β-L-xylopyranoside

Conclusions The-oxide ring of methyl-2,3-anhydro-4-O-benzyl--L-ribopyranoside is opened stereospecifically by dimethylmagnesium, and here methyl-3-desoxy-3-C-methyl-4-O-benzyl--L-xylopyranoside is formed quantitatively.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 460–463, February, 1977.     

Synthesis of macrolide antibiotics. 1. Synthesis of the C1-C6 segment of 14-membered macrolide antibiotics.

The C₁-C₆ segment of a number of 14-membered macrolide antibiotics have been synthesized started from levoglucosan.     

Synthesis of macrolide antibiotics. 22. Synthesis of the C8-C13 fragment of oleandonolide

The stereospecific synthesis of the C⁸-C¹³ fragment of oleandonolide was carried out in 15 steps with an overall yield of 4.48%.For previous communication, see [1].Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2136–2142, September, 1991.     

Synthesis of macrolide antibiotics. 2. Synthesis of the C9-C13 segments of erythronolides A,B and oleandonolide

The C₉-C₁₃ segments of some 14-membered macrolide antibiotics have been synthesized from levoglucosan.