The title keto acid, C(16)H(18)O(3), displays significant twisting of all three ethyl-ene bridges in its bicyclo-[2.2.2]octane structure owing to steric inter-actions; the bridgehead-to-bridgehead torsion angles are 13.14 (12), 13.14 (13) and 9.37 (13)°. The compound crystallizes as centrosymmetric carboxyl dimers [O⋯O = 2.6513 (12) Å and O-H⋯O = 178°], which have two orientations within the ce...

Here we provide definitive EPR evidence for the existence of α-triphenylstannylvinyl radicals such as (Z)-2 in low temperature O-directed free radical hydrostannation dialkyl propargylic alcohols with Ph3SnH/cat. Et3B and O2 PhMe.

The stereocontrolled synthesis of oligodeoxyribonucleoside phosphorothioates (PS-ODNs) using nucleoside 3'-O-oxazaphospholidine derivatives as monomer units is described. 2-Chloro-1,3,2-oxazaphospholidine derivatives were prepared from six kinds of enantiopure 1,2-amino alcohols and used for the phosphitylation reactions of 5'-O-protected nucleosides. A detailed study of these reactions reveale...

The scope of applications of dialkyl dicyanofumarates and maleates as highly functionalized electron-deficient dipolarophiles, dienophiles and Michael acceptors is summarized. The importance for the studies on reaction mechanisms of cycloadditions is demonstrated. Multistep reactions with 1,2-diamines and β-aminoalcohols leading to diverse five- and six-membered heterocycles are discussed. Appl...

An efficient synthesis of trialkyl (E)-3-(3-Oxo-2-3,4-dihydro-2-(1H)-quinoxalinylidene)-prop-1-ene-1,2,3-tricarboxylate derivatives via a simple three-component reaction between benzene-1,2-diamines with dialkyl acetylenedicarboxylates in the presence of K2CO3-PEG catalytic system at 100 oC was reported. The desired products were obtained in excellent yields (88-92%). Various benzene-1,2-diamin...

the kinetics of the reactions between triphenylphosphine 1 and dialkyl acetylenedicarboxylates 2, in the presence of a nh-acid such as 5-nitroindazole 3,were studied. corresponding kinetic parameters to all reactions were evaluated, with the second order rate constant (k) values calculated. effects of solvent, temperature, and reactants (dialkyl acetylenedicarboxylates) structure and concentrat...

The title compound, C(9)H(14)N(2)O, exists in the zwitterionic form in the crystal. The cyclo-octane ring adopts a twisted boat-chair conformation. In the crystal, inter-molecular N-H⋯O hydrogen bonds link the mol-ecules into sheets lying parallel to bc. The structure is also stabilized by π-π inter-actions, with a centroid-to-centroid distance of 3.5684 (8) Å.

The synthesis of the title compounds was carried out by reacting dicarboxylic acid chlorides with oximes in the presence of excess triethylamine. Disubstituted malonyl chlorides gave 2-alkenyl-4,4-dialkyl-3,5-isoxazolidinediones (8a-f) and 2,2'-ethylidene-bis[4,4-dialkyl-3,5-isoxazolidinedione]s (9a-f). Compounds 9 were formed from 8 and its N-unsubstituted 3,5-isoxazolidinedione decomposition ...