178491-58-2Relevant articles and documents
Stereospecific Synthesis of β-D-Fructofuranosides Using Thioglycoside Donors and Internal Aglycon Delivery
Krog-Jensen, Christian,Oscarson, Stefan
, p. 1780 - 1784 (2007/10/03)
Stereospecific synthesis of β-D-fructofuranosides has been accomplished by the application of an internal acceptor delivery approach. The acceptor, ethanol or monosaccharides, is initially tethered to the fructofuranose 3-hydroxyl group, adjacent to the anomeric center and on the β-side of the furanose ring, as part of a mixed p-methoxybenzaldehyde acetal, which is formed by DDQ-oxidation of ethyl 1,4,6-tri-O-benzyl-3-O-(4-methoxybenzyl)-2-thio-D-fructofuranoside in the presence of the acceptor or of the p-methoxybenzylated acceptor in the presence of the corresponding 3-OH fructofuranoside. Then, activation of the thioglycoside with a thiophilic promoter allows the delivery of the acceptor from the acetal to the activated anomeric center to yield the β-linked fructofuranoside in high yields (76-85%). If promoters with nonnucleophilic anions (triflate, perchlorate) are used, the intermediate acetal decomposes to produce the β-fructofuranoside products as 3-OH derivatives. However, if NIS is used as promoter, the N-succinimide anion interacts with the benzylidene carbon to give the β-fructofuranoside products as mixed fructofuranoside-3-O-yl N-succinimide p-methoxybenzaldehyde acetals.