The NMR study of derivatives of substituted inosine – The precursors of AICAr

In this article we describe how the simultaneous presence and interaction of the aromatic ring at position 1 of an inosine derivative with the acetyl group at positions 2, 3, 5 of the furanose ring convert conformation of the nucleoside into the major conformer in solution. During the synthesis of AICAr, we obtained products (A and B) of inosine protected with 2,4-dinitrochlorobenzene, with two sets of NMR signals, each with very similar chemical shifts. Analysis of experimental NMR spectra and theoretical GIAO – DFT calculations were performed to obtain information about the stereochemistry of the products.