K. Lyssenko, D. Lenev, R. G. Kostyanovsky
Oct 14, 2002
Citations
0
Influential Citations
21
Citations
Journal
Tetrahedron
Abstract
Abstract Synthesis of racemic and enantiomeric 2,5-diazabicyclo[2.2.2]octane-3,6-dione-dicarboxylic acids and their diesters, as functionalized building blocks for supramolecular chemistry, is described. It is shown that heterochiral H-bonded zigzag tape with R22(8) graph and molecular ‘brick wall’ with a non-polar coating are persistent and stable motifs in the crystal structures of the racemic dialkyl 2,5-diazabicyclo[2.2.2]octane-3,6-dione-1,4-dicarboxylates ( 1 , 5 , 11 ). This stability was confirmed by quasi-racemate [CD(−)230]-1 · 4 formation and crystal structure determination. Packing of the diacids (±)-2 and (−)-2 dihydrates differed from that of esters, with H2O molecules linking homochiral spirals, into corrugated homochiral layers, observed in both structures. The crystal structure of enantiomeric diester (−)-1 contained spirals similar to those observed in diacids with participation of the ester carbonyl groups in H-bonding.