Stereospecific synthesis of octaprenols WT3C4OH and WT3C3TOH

A total synthesis of the above prenols has been carried out.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2333–2338, October, 1991.     

A highly efficient type I β-turn mimetic simulating an Asx-Pro-turn-like structure

Asx-Pro-turns have been identified with high frequency in protein structures nucleating type I β-turns. By bridging the amino acid side chain in position i with a nitrogen substituent in position i+2 by ring-closing olefin metathesis (RCM), peptide mimetics of type 1 could be developed. NMR based conformational investigations indicated a stable intramolecular H-bond constraining a U-turn conformation that was predicted to simulate a type I β-turn.     

Synthesis of Z,Z-Trishomofarnesal tert-butylimine

A highly stereoselective method was developed for the preparation of Z,Z-trishomofarnesal tert-butylimine, a key block synthone required for the construction of polyprenols with a nonnatural configuration of the head end of the chain, using as a basis the controlled condensation of aldehydes with aldimines. It was shown that introduction into the condensation of aldehydes containing an acetal grouping at the -position results in the formation of considerable amounts of aldols. The use of -trimethylsilyl derivatives of aldimines makes it possible to dispense with this process and to direct the reaction toward the desired Eacroleins.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimieheskaya, No. 1, pp. 97–107, January, 1990.     

Synthesis of Dolichyl Phosphates with a Fluorescent Label in the gamma-Isoprene Unit of the Chain

Stereoselective synthesis of the dolichyl phosphate derivatives WT₃C₂S-OP and WT₂C_6,7S-OP* containing the 1-naphtylamino group in the gamma-isoprene unit of the chain was performed. The synthetic scheme includes directed aldol condensation to construct (E)-alfa,beta-disubstituted acroleins, their reductive amination with 1-aminonaphthalene, and phosphorylation of the resulting amino alcohols.     

More Sublattices of the Lattice of Local Clones

We investigate the complexity of the lattice of local clones over a countably infinite base set. In particular, we prove that this lattice contains all algebraic lattices with at most countably many compact elements as complete sublattices, but that the class of lattices embeddable into the local clone lattice is strictly larger than that: For example, the lattice M_2^wM_{2^\omega} is a sublattice of the local clone lattice.     

Z-Stereoselective Peterson olefination of ketones

A highly-stereoselective method (90 % of theZ-isomer) was developed for the Peterson olefination of ketones with nerylacetone (1) as an example. The method is based on the introduction of a PhS group, which is removed after completion of the reaction, at the ketone C(3) atom.DeceasedFor the perliminary communication, see Ref. 10.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 509–516, March, 1995.The authors are grateful to the Russian Foundation for Basic Research (grant No. 94.03.08904) and the International Science Foundation (grant NGO000) for financial support of this work.     

Highly stereoselective synthesis of a sex pheromone of the dry bean beetleCallosobruchus analis

Total synthesis of 3-methylhept-2(Z)-enoic acid, a sex pheromone of the dry bean beetleCallosobruchus analis, has been performed using a previously developed highly stereoselective method of the construction of disubstituted (Z)-methylolefins based on the higher thermodynamic stability of (E)-isomers of α,β-disubstituted acroleins. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1385–1388, July, 1999.