Showing papers by "Stephen Hanessian published in 1974"
TL;DR: The condensation of 2,3,4,6,6-tetra-O-acetyl-α-D-glucopyranosyl bromide with sodio diethyl malonate led to crystalline 2.
Abstract: The condensation of 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl bromide with sodio diethyl malonate led to crystalline diethyl 2-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl) malonate. The correspondin...
36 citations
TL;DR: In this paper, the condensation of D-ribofuranosyl halides containing participating (benzoate) and non-participating (benzyl) substituents, with sodio dialkyl malonates and sodio triethyl 1,1,2-ethanetricarboxylate is described.
Abstract: The condensation of D-ribofuranosyl halides containing participating (benzoate) and non-participating (benzyl) substituents, with sodio dialkyl malonates and sodio triethyl 1,1,2-ethanetricarboxylate is described. In the presence of participating groups at C-2, the major and sometimes exclusive products were the 1,2-ketal derivatives. Both α- and β-anomeric D-ribofuranosyl malonates were formed in the non-participating series. The possibility of epimerization (anomerization) was experimentally demonstrated.Similar results were obtained with the more highly functionalized tricarbethoxy carbanion. For the participating series however, 20% of C-glycoside was obtained. Condensations with sodio diethyl malonate were also done in the D-arabino series (O-benzyl protecting group) and the anomeric C-glycosyl compounds were isolated and characterized. The mechanistic aspects of these condensations are discussed.
29 citations
23 citations
13 citations
12 citations
11 citations
9 citations
5 citations
TL;DR: Reactions are described that lead to an immediate, chemical precursor of kasugamine the amino-sugar component of the aminocyclitol antibiotic kasUGamycin.
5 citations
TL;DR: The title compound containing a phenylthio group at C-3 and a methanesulfonate group at c-2 undergoes a quantitative transposition reaction in refluxing benzene to give the diequatorial isomer.
Abstract: The title compound containing a phenylthio group at C-3 and a methanesulfonate group at C-2 undergoes a quantitative transposition reaction in refluxing benzene to give the diequatorial isomer. In DMSO, a complex reaction takes place leading to elimination and oxidation at C-2. Oxidation of the title compound containing a phenylthio group at C-2, with acetic anhydride–DMSO gives the corresponding 3-uloside. With the isomeric 3-phenylthio derivative the enol acetate is formed. These results are rationalized based on mechanistic considerations.
3 citations