Koenigs-Knorr reaction, synthesis oligosaccharides

Helferich, Bohm and Winkler1 have reported that the use of iodine catalyzed the Koenigs-Knorr reaction, which was exceedingly slow when calcium chloride was used as an internal desiccant. This catalyst has since been used by a number of other workers.79 111-114 The work of Talley, Reynolds and Evans79 on the synthesis of the orthoester type of oligosaccharides, indicated that the presence of iodine favored the formation of a normal biosidic linkage, whereas the absence of iodine favored the formation of an orthoester linkage. 

The synthesis of oligosaccharides on polymer supports by using the Koenigs-Knorr reaction has been studied by several groups.140-145 Frechet and Schuerch140,141 used poly[p-(3-hydroxy-l-propenyl)sty-rene] (82) ((P)—CH=CH—CH2OH) as a polymer support, and allowed... 

The first polymer-supported oligosaccharide synthesis by Schuerch s group employed the Koenigs-Knorr reaction and its variants, using an immobilized glycosyl acceptor on an organic solid polymer (Scheme 1) [14]. It was followed by inves-... 

---