Radicals glucopyranosyl

This different behavior can be explained by the conformation of the radicals and by stereoelectronic effects [6]. Electron spin resonance (ESR) investigations have revealed that the D-glucopyranosyl radical 7 does not adopt the 4C1 conformation 7a, but is distorted into the B2 5 shape 7b (Scheme 5) [7,8], The equatorial-like attack at the boat conformer... 

Figure 7.5 Orbital alignment in the glucopyranosyl radical. The top shows the unoccupied, singly occupied and doubly occupied atomic orbitals involved, the bottom a pictorial valence bond representation of the same phenomenon.

The azide radical can be generated thermally by treatment of ethylsulfonyl azide at 100 This can be coupled with the 3,4,6-tri-0-acetyl-2-deoxy-D-glucopyranosyl radical obtained in turn from the xanthate 125 to give the a-o-araZ)/ o-hexopyranosyl azide 15 in good yield. " " ... 

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