Synthesis of phosphoramidites of isoGNA, an isomer of glycerol nucleic acid.

IsoGNA, an isomer of glycerol nucleic acid GNA, is a flexible (acyclic) nucleic acid with bases directly attached to its linear backbone. IsoGNA exhibits (limited) base-pairing properties which are unique compared to other known flexible nucleic acids. Herein, we report on the details of the preparation of isoGNA phosphoramidites and an alternative route for the synthesis of the adenine derivative.

Exploratory experiments on the chemistry of the "glyoxylate scenario": formation of ketosugars from dihydroxyfumarate.

In the context of a "glyoxylate scenario" of primordial metabolism, the reactions of dihydroxyfumarate (DHF) with reactive small molecule aldehydes (e.g., glyoxylate, formaldehyde, glycolaldehyde, and glyceraldehyde) in water were investigated and shown to form dihydroxyacetone, tetrulose, and the two pentuloses, with almost quantitative conversion.

SUBTLE CONTROL IN SOLUTION AND CRYSTAL STRUCTURES WITH WEAK HYDROGEN BONDS: THE UNUSUAL PROFILE OF DIMETHYL 3, 12-DIOXO-7, 8 DITHIA 4, 11-DIAZABICYCLO[12.2.2]OCTADECA-1(16), 14, 17-TRIENE 5, 10-DICARBOXYLATE (TDA1).

The structural features of the title compound were determined or examined by three diverse procedures: single crystal X-ray diffraction analysis, solution spectroscopic procedures and Quantum mechanical theoretical calculations. The conformational asymmetry of the macrocycle provides the opportunity to form one strong NH···OC intermolecular hydrogen bond, as well as, a number of weak CH···OC bonds. The interior of the macrocycle has short approaches for NH(.

Diphenic acid as a general conformational lock in the design of bihelical structures.

The bihelical (figure of "infinity") topology was examined from vantages of design, crystal structures, chirality, circular dichroism (CD) studies and molecular-orbital calculations. The minimalistic design envisaged the sequential linking of cystine to the anchor diphenic acid, which proved to be a general conformational lock. The bihelical compound 4 was obtained in two steps from diphenic anhydride 1 and cystine di-OMe.