Structure and Conformation of Septanosides

SCHEME 13.24 Metal-catalyzed cross-coupling reactions on bromo-oxepine 65 [33], 

SCHEME 13.26 Synthesis of 2-chloro-2-deoxy septanoside derivative 94 [32]. 

Studies on conformations of septanosides in the solid-state, solution-phase, and computational methods are still limited, unlike in the case of naturally occurring furano-sides and pyranosides for which finer details of the conformations are well elucidated [34]. Being a larger ring system, septanosides are more flexible, leading to attenuation of more complex pseudorotational equilibria, with energy barriers among 

FIGURE 13 Molecular and solid-state structures of septanosides 95 and 97. 

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