41341-73-5Relevant articles and documents
Caveat in alkylative fragmentation of aldehyde tosylhydrazones of cyclic ethers
Chandrasekhar,Reddy, M.Venkat,Takhi, Mohamed
, p. 6535 - 6538 (1998)
Tosylhydrazones of aldehydes at the α-position of cyclic ethers when exposed to carbon nucleophiles produce either ring opened alkylated olefinic alcohols and/or cyclic alkylated vinyl ethers, the ratio of which is dependent on nature of hydrazone and nucleophile used.
Fluorination Reactions at C-5 of 3-O-Benzyl-6-deoxy-1,2-isopropylidenehexofuranoses
Mori, Yoko,Morishima, Naohiko
, p. 236 - 241 (2007/10/02)
Fluorination reactions of 2-O-benzyl-6-deoxy-1,2-O-isopropylidene-α-D-gluco-, β-L-ido-, α-D-allo-, and β-L-talo-furanoses (1, 2, 3, and 4) were investigated.The reaction of 1 with diethylaminosulfur trifluoride (DAST) predominantly produced 2-O-benzyl-5,6-dideoxy-5-fluoro-1,2-O-isopropylidene-α-D-glucofuranose with the retention of the configuration at C-5.Both of the fluorides with retained and inverted configurations were obtained in the fluorination of 2 with DAST.In contrast, only the inversion of the configuration occurred when 3 and 4 were reacted with DAST.The reactions of the methanesulfonates of 3 and 4 with tetrabutylammonium fluoride (TBAF) and those of their trifluoromethanesulfonates with tris(dimethylamino)sulfonium difluorotrimethylsilicate (TASF) gave the 5-deoxy-5-fluoro derivatives with the inversion of each configuration and the 5,6-unsaturated derivative.However, the reactions of the sulfonates of 1 and 2 overwhelmingly produced the 4,5- and 5,6-eliminated derivatives.For the reaction in which the steric hindrance of the benzyloxyl group at C-3 and the electronic repulsion of ring oxygen to the SN2 displacement with fluoride anion are significant, such as the fluorination of 1 with DAST, the SNi mechanism is reasonable.
Chiral Building Units from Carbohydrates, XI. - 2-Lithio-1,3-dithiane-induced Reactions of 5,6-Dideoxy-5-iodohexofuranoses Leading to Open-chained Heptose Trimethylene Dithioacetals
Redlich, Hartmut,Lenfers, Jan Bernd,Bruns, Wilfried
, p. 1570 - 1586 (2007/10/02)
The reaction of 5,6-dideoxy-5-iodohexofuranoses 5b, 7c, 8, 8a, and 20 with a large excess of 2-lithio-1,3-dithiane (1) yields the open-chained heptose trimethylene dithioacetals 21, 23, 24, 25, and 26.L-Configurated 5-iodides give Z-olefines, D-configurat