Several possible scales of steric effects of the alkyl groups were suggested on the basis of isodesmic model reactions, in which a sterically crowded compound is formally synthesized from simpler derivatives. The reaction energies were calculated within the framework of the density functional theory at the level B3LYP/6-311+G(d.p)//B3LYP/6-311+G(d.p) for 6 model systems and 7 various alkyl grou...

Ethyl 2,3-diendo-3-aminobicyclo[2.2.2]oct-5-ene-2-carboxylate ((±)-1) was resolved with O,O'-dibenzoyltartaric acid via diastereomeric salt formation. The efficient synthesis of the enantiomers of 2,3-diendo-3-aminobicyclo[2.2.2]oct-5-ene-2-carboxylic acid ((+)-7 and (-)-7), 3-endo-aminobicyclo[2.2.2]oct-5-ene-2-exo-carboxylic acid ((+)-5 and (-)-5), cis- and trans-3-aminobicyclo[2.2.2]octane-2...

[reaction: see text] The beneficial influence of cis-isopropylidene acetal tether control groups, to facilitate the asymmetric synthesis of substituted decalins by intramolecular Diels-Alder reactions, is described. Compared to trans-acetonides, these cases proceed under milder conditions to afford the cis-fused adducts from an endo transition state. An unusual acetonitrile solvent effect exert...

Compounds I, II and III, were used as models resembling gear systems (bods connecting CR3 groups to the skeletal molecule are parallel) in surveying the potential energy surface for their internal rotation. The magnitude of the barriers calculated for averaging the NMR signals, placed these compounds in the range of measurement accessible by dynamic NMR spectroscopy (which is cur...

The synthetic potential of stereoselective, palladium-catalyzed hydro(het)arylation reactions of bi-, tri- and tetracyclic (hetero)alkenes in the presence of phospines and arsines as highly efficient ligands was studied. The mechanism of this reductive Heck reaction becomes more complex in the case of benzonorbornenes. Hydroarylation of diazabicyclo-[2.2.1]heptenes provides a stereoselective ac...

indandione 1 was brominated to yield 2-bromoindandione 2 which on further reacted with substituted thiocarbamides, carbamides, 2-aminothiophenols, 2-aminophenol and triazoles to furnished 3-substituted aniline-2-thia-4-aza-6,7-benzo-8-oxo-bicyclo [3.3.0]-1(5),3-octadiene 3, 3-substituted aniline-2-oxa-4-aza-6,7-benzo-8-oxo-bicyclo [3.3.0]-1(5),3-octadiene 4, 2-thia-5-aza-9-oxo-3,4-(3’-substitut...

2014 Proton n.m.r. relaxation time measurements have been made on bicyclo[2.2.2]octane (BCO) and bicyclo[2.2.2]oct-2-ene (BCOE). Measurements for each sample were made throughout the plastic and brittle phases, down to 77 K. The results have been interpreted in terms of the various molecular motions occurring in the solid. Below the plastic-brittle phase transition point anisotropic molecular r...