3-Lithiomethyl-4-phenylsydnone: A new type of organometallic derivatives of sydnones

An α-lithium derivative of 3-alkyl-substituted sydnone was first synthesized by direct metallation of 3-methyl-4-phenylsydnone withn-butyllithium. The reactivity of the compound obtained was studied. Reactions of 3-lithiomethyl-4-phenylsydnone with various electrophiles can serve as a convenient method for preparation of functionalized sydnones.     

Structure of 1,7-diphenyl-m-carborane

Journal of Structural Chemistry -     

Structure of organophosphorus compounds

Journal of Structural Chemistry -     

Structure of pseudostichoposide A — The main triterpene glycoside from the holothurian Pseudostichopus trachus

A holostane oligoglycoside — pseudostichoposide A — has been isolated from the holothurianPseudostichopus trachus Sluiter, collected on the oceanic side of the island of Urup (Kurile Islands). Its structure has been established with the aid of¹³C and¹H NMR spectroscopy and partial acid hydrolysis with sulfuric acid in the presence of butanol as 3β-{O-(3-O-methyl-β-D-quinovopyransoyl-(1 → 3)-O-β-D-xylopyranosyl-(1 → 4)-O-β-D-quinovopyranosyl-(1 → 2)-[4-O-(sodium sulfato)-β-D-xylopyranosyloxy]}-holost-7-en-22-one. Its native genin, which has been called urupogenin (3β-hydroxyholost-7-en-22-one) was obtained on partial hydrolysis in the form of an individual compound. It is a new holostane derivative.     

Structure-NMR chemical shift relationships for novel functionalized derivatives of quinoxalines

(1)H, (13)C and (15)N NMR chemical shifts for a variety of novel quinoxalines were determined by different 2D methods and were calculated using the GIAO DFT approach. Comparison with experimental data shows good correlations in the case of (1)H, (13)C and (15)N chemical shifts. Different combinations of basis sets were tested. In non-polar solvents quinoxalines exist as dimers owing to strong hydrogen bonding. Calculations for dimers improve the correlation between experiment and theory. Additive empirical methods for estimating chemical shifts have drawbacks and have to be used with a great care for this type of compound.     

Effect of cross-conjugation on properties of α-mercurated carbonyl compounds

Conclusions The polarographic data and the data of the IR spectra of the-mercurated esters of the cinnamic and crotonic acids show that in these compounds the- conjugation of the C-Hg bond with the C=O group is weakly expressed, and may be completely absent.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1912–1913, August, 1973.     

Synthesis of 2-butyl-4,9-decadienoic and 2-butyl-4,9-dimethyl-4,9-decadienoic acids,structural analogues of cygerol

2-Butyl-4,9-decadienoic and 2-butyl-4,9-dimethyl-4,9-decadienoic acids, structural isomers of 2-cyclohexylgeranylacetic acid, which is an active component of the wound healing ointment cygerol, have been synthesized. Hydrocarbon chains C₁₀ have been obtained by the one-pot method of formation of long-chain hydrocarbons, namely, by the telomerization reaction of 1,3-dienes with nucleophiles catalyzed by palladium complexes. A heterogeneous palladium-zeolite catalyst has been used for the first time in telomerization of isoprene with piperidine.     

Cascade cycloaddition reactions involving dimethylhydrazones of α-substituted acroleins

Unusual cascade cycloaddition reactions with dimethylhydrazones of -trimethylsilyloxyalkylacroleins acting as azadienes were found. Depending on the nature of the dienophile, the reactions give either fused heterocyclic compounds (when two consecutive Diels—Alder reactions take place) or azabicyclic compounds, resulting from the [2+4]- and [2+3]-cycloaddition cascade.