中文名称 | 英文名称 | CAS号 | 化学式 | 分子量 |
---|---|---|---|---|
—— | dimethyl 4,5-di-O-acetyl-2,6-anhydro-3-deoxy-D-xylo-hept-2-enarate | 58262-13-8 | C13H16O9 | 316.265 |
—— | (-)-(5R,6R)-3,5-Bis(acetoxy)-6-(acetoxymethyl)-5,6-dihydro-2H-pyran-2-one | 122359-37-9 | C12H14O8 | 286.238 |
—— | 2,4,6-tri-O-acetyl-3-deoxy-α-D-threo-hex-2-enopyranosyl cyanide | 83938-04-9 | C13H15NO7 | 297.265 |
—— | 2,4,6-tri-O-acetyl-3-deoxy-β-D-threo-hex-2-enopyranosyl cyanide | 83938-05-0 | C13H15NO7 | 297.265 |
—— | 1,2,4,6-Tetra-O-acetyl-3-desoxy-α-D-threo-hex-2-enopyranose | 14125-89-4 | C14H18O9 | 330.292 |
—— | 1,2,4,6-Tetra-O-acetyl-3-desoxy-β-D-threo-hex-2-enopyranose | 70532-55-7 | C14H18O9 | 330.292 |
Benzyl and 2-propyl 6-O-acetyl-3,4-dideoxy-α -D-glycero-hex-3-enopyranosid-2-uloses (2) and (3) were readily prepared by the tin(IV) chloride-promoted glycosylation of glycal (1). The enone system of (2) and (3) underwent a highly diastereoselective Michael addition of thiols (ethanethiol, propane-2-thiol, and benzenemethanethiol) to afford the sulfur-containing hexopyranosid-2-ulose derivatives (4a-c) and (5a-c) in good yields. Sodium borohydride reduction of the carbonyl functionalities of (4b,c) and (5b) led to the corresponding 3-deoxy-4-thiohexopyranosides having the D-xylo (6b), (6c), and (8b) or the D-lyxo (7b), (7c), and (8c) configuration. Standard acetylation of these compounds gave the corresponding per-O-acetyl derivatives (10b), (10c), and (12b) and (11b), (11c), and (13b), useful for confirming all the previous configurational assignments by means of their 1H and 13C nuclear magnetic resonance spectra. Furthermore the 2-ulose (5b) proved to be a key intermediate for the synthesis of C-2 branched-chain 4-thiopyranosides, such as (16). The latter was synthesized by a good yielding ammonium acetate-catalysed Knoevenagel-type condensation of malononitrile with (5b).