The title compound, C10H22N2 (2+)·2Br(-), was synthesized via reduction of 2,2'-dipyridyl with Ni-Al alloy/KOH, followed by separation of diastereoisomers (meso and rac) by recrystallization from ethanol. Although the two bridging C atoms are optically active, these two chiral centers adopt an (S,R) configuration; thus, the title compound contains an achiral meso form of 2,2'-bi-piperidine. Bot...

Two optically active (100% enantiomeric excess) isomers (13a and 13b) of ofloxacin (1) [(•})ofloxacin; DL-8280; (•} )-9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl1 -piperazinyl)-7-oxo-7Hpyrido[1,2,3-de][1,4]benzoxazine-6-carboxylic acid] and their fluoromethyl derivatives (14a and 14b) were prepared via their optically active intermediates resolved by use of high-performance liquid chromatography...

A C2-symmetric enantiopure 4,5-bis(pinene)-2,2'-bipyridine ligand (-)-L was used to investigate the diastereoselectivity in the formation of [ML3]2+ coordination species (M = Fe(II), Ru(II), Os(II), Zn(II), Cd(II), Cu(II), Ni(II)), and [ML2Cl2] (M = Ru(II), Os(II)). The X-ray structures of the [ML3]2+ complexes were determined for Delta-[FeL3](PF6)2, Delta-[RuL3](PF6)2, Lambda-[RuL3](PF6)2, Del...

The reaction of glycine-N-methyl amide with paraformaldehyde in the presence of ytterbium triflate (1 mol%) leads to a novel cage structure 6 which is chiral at nitrogen. Single crystal X-ray analysis and DFT calculations suggest this cage structure is rigid and adopts a single low energy conformation. Use of single enantiomer α-amino amides results in two diastereomeric tertiary amines that di...

ABSTRACT Knoevenagel condensation of barbituric acids with aromatic aldehydes containing one or two formyl groups was carried out. 5-Arylidenebarbituric acids underwent smooth hetero-Diels-Alder (HDA) reactions with enol ethers to afford cis and trans diastereoisomers of pyrano[2,3-d]pyrimidine-2,4-diones and 5,5'-(1,4-phenylene)bis[2H-pyrano[2,3-d]pyrimidine-2,4(3H)-dione] derivatives in excel...

Heating one of the most abundant naturally occurring inorganic chemicals (elemental sulfur) with one of the most readily available homochiral molecules (limonene) gives a one-step synthesis of a chiral sulfide which exhibits outstanding selectivities in sulfur ylide mediated asymmetric epoxidations and aziridinations. In particular reactions of benzyl and allylic sulfonium salts with both aroma...

Using molecular mechanics (MM2, MM3) and semiempirical molecular orbital methods (EHMO, AMI, PM3) the relative energies were estimated from models for the tetrahedral intermediates in N->0 and o~N acyl migration in diastereoisomers of 3-amino-1,2,3triphenylpropanol to check the necessity of invoking a stereoe!ectronic effect to explain their reactivities . The molecular mechanics results correc...

A full theoretical study of the reaction between a novel type of ylide, i.e. nitrone ylides, and alkenes has been carried out. Both concerted and polar stepwise mechanisms have been considered. Only the zwitterionic mechanism predicts correctly the experimentally observed adducts. Depending on the level of theory, the mechanism moves from concerted to polar stepwise, as demonstrated by the corr...

Our previously conducted pharmacological investigations led us to discovery of the strong local anesthetic activity of the compound KP-23RS. The following studies revealed that its Rand S-diasteroisomers had different activity in the local anesthetic, anti-aggregating, anti-arrhythmic and spasmolytic tests. Also the influence of KP-23RS and its diastereoisomers on the cyclic adenosine monophosp...