Special Problems in Glycosylation Reactions: 2‐Deoxy Sugars

2-Deoxy-2-iodo-β-glucopyranosyl Fluorides: Mild and Highly Stereoselective Glycosyl Donors for the Synthesis of 2-Deoxy-β-glycosides from β-Hydroxy Ketones

“…Optimization of the glycosidation with TBSOTf (0.3 equiv) as the promoter led to a disappointing 21% yield of the desired glycosylated product 13 but with excellent anomeric selectivity (β : α > 98: 2) . This example further confirms that TBSOTf is superior to TMSOTf for the glycosidation reactions of sensitive substrates. 2b,, However, to achieve a synthetically useful glycosidation procedure with aldol acceptors, it was clear that almost neutral activation conditions of the donor would be required 2 Glycosidation Reaction of β-Hydroxy Ketone 12 …”

“…2-Deoxy-glycosides are important structural units found in numerous natural and biologically active compounds such as the angucycline family of antibiotics (landomycin A), the aureolic acid antibiotics (olivomycin A, chromomycin A 3 ), the enediynes (calicheamycin γ 1 I , esperamicins A 1 and C), the avermectins (avermectin B 1a , ivermectin), some cholestane glycosides (OSW-1), and cardiac glycosides . Although some general methods have been developed for the stereoselective construction of 2-deoxy-α-glycosidic linkages (mainly by electrophilic addition to glycals), preparation of the corresponding β-linkage has proved to be much more difficult. Our group has been involved in the development of new methods of synthesis of this challenging 2-deoxy-β-glycosidic linkage. − We previously reported that 2-deoxy-2-iodo-β-glucopyranosyl acetates 1 4 and 2-deoxy-2-iodo-α-glucopyranosyl trichloroacetimidates 2 5 are highly reactive glycosyl donors for establishing β-linked glycosides.…”

Automated Chemical Oligosaccharide Synthesis: Novel Approach to Traditional Challenges

“…These special cases of glycosylation include the following major classes of compounds. 2-Deoxysugars, , that are discussed in a separate review in this special issue . 2-Amino-2-deoxy sugars require additional steps and a careful selection of suitable protecting groups at C-2, most commonly 2,2,2-trichloroethoxycarbonyl (Troc) or phthaloyl (Phth), for the synthesis of 1,2-trans and azide for the synthesis of 1,2-cis linked glycosides.…”

Synthesis and Preliminary Anticancer Activity Assessment of N-Glycosides of 2-Amino-1,3,4-thiadiazoles

“…On the other hand, glycals are versatile building blocks in carbohydrate synthetic chemistry and have been extensively investigated for the synthesis of 2-deoxy- O -, S -, N -glycosides. The method for entry into 2-deoxy glycosides has been discussed in several reviews [ 31 , 32 , 33 , 34 , 35 ].…”