Synthesis and ab initio conformational investigation of a series of model sulfated α-L-iduronopyranosides

Due to the all-axial orientation of the OH-groups in the 1C4 chair conformation considered standard for L-hexapyranosides, including l-iduronopyranoside – a component of many biologically and medically significant sulfated glycans, these monosaccharides can be anticipated to display unusual conformations upon the introduction of bulky and charged substituents. Herein we describe the synthesis of a series of iduronopyranoside derivatives with varying sulfation patterns, which were studied computationally using the DLPNO-MP2 approach and by means of analyzing their chemical shifts to ascertain the effects sulfation has on the conformation of the iduronopyranoside ring.