Exploitation of in Situ Generated Sugar-Based Olefin Keto-Nitrones: Synthesis of Carbocycles, Heterocycles, and Nucleoside Derivatives

Abstract

Application of intramolecular 1,3-dipolar nitrone cycloaddition reaction on carbohydrate-derived precursors containing an olefin functionality at C-1 or C-3 or C-5 and a nitrone moiety at C-2 or C-3 as appropriate has resulted in the formation of structurally new cycloaddition products containing furanose-fused oxepane, thiepane, azepane, cyclopentane, cycloheptane, tetrahydrofuran, and pyranose-fused tetrahydrofuran rings. The structure and stereochemistry of these products have been characterized by spectral as well as single-crystal X-ray analyses. Two of the compounds have been transformed to the bicyclic nucleoside derivatives applying Vorbrüggen reaction conditions.

Total Synthesis of Natural Disaccharide Sambubiose

“…Both 10 and 11 were not assessed as acceptors in the glycosylation reaction. Finally, our attention was turned to the glycoside acceptor allyl 3,5,6-tri- O -benzyl-D-glucofuranoside ( 12 , Figure 2 ) which was prepared in an acidic environment by treating 2 with allyl alcohol [ 17 ] giving an α/β 1:1.1 mixture ( Scheme 2 ).…”

“…Both 10 and 11 were not assessed as acceptors in the glycosylation reaction. Finally, our attention was turned to the glycoside acceptor allyl 3,5,6-tri-O-benzyl-D-glucofuranoside (12, Figure 2) which was prepared in an acidic environment by treating 2 with allyl alcohol [17] giving an α/β 1:1.1 mixture (Scheme 2). With regard to the donor glycoside, only compounds that are more stable than 5a (Scheme 1), such as fluoride [18] and trichloroacetimidate [19] protection and deprotection of functional groups which also guide the regioselective reaction progress.…”

Quinoline–Glycomimetic Conjugates Reducing Lipogenesis and Lipid Accumulation in Hepatocytes

“…Synthesis of the quinoline–galactosamine conjugate ( 3 ) was achieved by conjugating quinoline derivative 2 with the galactosamine azide ( S2 ) through the CuAAC reaction followed by deprotection under acidic conditions (Scheme B). Furthermore, a glucofuranoside derivative, S3 , was also synthesized and conjugated with 2 through the CuAAC reaction to yield compound 4 (Scheme C).…”

Tetrathiomolybdate and Tetraselenotungstate as Sulfur/Selenium Transfer Reagents: Applications in the Synthesis of New Thio/Seleno Sugars

“…This could be seen in the synthesis of sulfur heterocycles ranging from three membered to eight membered ring systems and especially in the synthesis of bioactive seven membered ring compounds (thiepane derivatives). [20,32] A simple C 2 -symmetric enantiopure N-Boc/tosyl protected 1,3-bis-aziridines 71 have been synthesized from D-tartaric acid. Reaction of bis-aziridine 71 with 1 [1.2 equiv, CH 3 CN, 28 °C, 4 h], furnished the C 2 -symmetric cyclic sulfide derivative 72 and cyclic disulfide derivative 73 (1 : 1) in good yields (Scheme 19).…”