Data on the productivity of plant cover of the main types of soils of the North-Western precaspian in connection with the dynamics of ecological factors.

The data of the researches describes the were to establish the species composition of pasture cenoses and the productivity potential of light-chestnut and meadow-chestnut soils under different climatic conditions and in different periods of the year in the Terek-Kuma lowland of the North-Western Precaspian. Two peaks of productivity of phytocoenosis have been observed: the first is - ephemeral synusia in the middle of May- early June; second - motley grass and saltworts in the second half of September. The data on receipt of photosynthetically active radiation (PAR) on the soil surface and the coefficient of its use over the years and periods of the year depending on the hydrothermal conditions and dynamics of harmful salts in the soil are given.

Explorations on the asymmetric total synthesis of isoschizogamine.

Two approaches to the synthesis of isoschizogamine were reported. Both routes utilized an efficient aza-Claisen rearrangement to establish the absolute stereochemistry of the all-carbon quaternary center in the natural product. In the first approach, a highly diastereoselective (10:1) hetero-Diels-Alder reaction was utilized to reach a densely functionalized tetrahydroquinoline derivative as an advanced intermediate to the targeted alkaloid.

Phosphine-mediated coupling of gramines with aldehydes: a remarkably simple synthesis of 3-vinylindoles.

A new and practical synthesis of terminally substituted 3-vinylindoles is described involving tributylphosphine-mediated coupling of gramines with aldehydes.

Chemoselective cyclizations of divinyl ketones to cyclohexenones mediated by Lewis acid and base.

[reaction: see text] Chemoselective cyclizations of divinyl ketones to cyclohexenones mediated by a sterically demanding Lewis acid and an amine base have been accomplished under mild reaction conditions. The extension of this methodology to the synthesis of eight-membered rings is also demonstrated.

Remarkably facile hexatriene electrocyclizations as a route to functionalized cyclohexenones via ring expansion of cyclobutenones.

This Communication describes a cascade reaction sequence that leads to highly functionalized cyclohexenones starting from reaction of cyclobutenones with alpha-lithio-alpha,beta-unsaturated sulfones and amides. The hexatriene-cyclohexadiene cyclization steps presumed to be involved in these transformations are among the most facile hexatriene electrocyclizations reported thus far.