The invention of radical reactions. Part XXXVIII. Homologation of car☐ylic acids with acrylamide and synthetic studies of 3-deoxy-D-arabino-2-heptulosonic acid (DAH) and its 4-epimer
作者:Derek H.R. Barton、Wansheng Liu
DOI:10.1016/s0040-4020(97)00543-7
日期:1997.8
Alkyl radicals generated from O-acyl derivatives of N-hydroxy-2-thiopyridone added onto acrylamide at room temperature to form crystalline 2-(2-pyridylsulfanyl)-car☐amides. Desulfurization of the latter by nickel boride at room temperature afforded primary amides in quantitative yield. 3-Deoxy-D-arabino-2-heptulosonic acid (DAH), its 4-epimer, and their derivatives were effectively synthesized from
Dioxalanones as synthetic intermediates. Part 6. Synthesis of 3-deoxy-D-manno-2-octulosonic acid (KDO), 3-deoxy-D-arabino-2-heptulosonic acid (DAH) and 2-keto-3-deoxy-D-gluconic acid (KDG)
作者:Robert Ramage、Angus M. MacLeod、Graeme W. Rose
DOI:10.1016/s0040-4020(01)80993-5
日期:1991.7
Three biosynthetically significant α-keto acids KDO (7), DAH (8) and KDG (9) have been synthesised via 5-ylidene-1,3-dioxalan-4-one intermediates formed by Wittig reactions of protected monosaccharide-derived aldehydes with the Wittig reagent (3).
A new and concise synthesis of 3-deoxy-D-arabino-2-heptulopyranosonic acid (DAH) and derivatives through the radical chemistry of Barton esters
作者:Derek H.R. Barton、Wansheng Liu
DOI:10.1016/s0040-4039(96)02331-3
日期:1997.1
Barton ester-based radical chemistry was applied in the synthesis of 3-deoxy-D-orobino-2-heptulopyranosonic acid (DAH) from commercial D-ribonolactone, The radical reaction with olefin 2, followed by aqueous work-up, provided the seven-carbon sugar compounds 5 and 6 (3:1) in 60% yield. Removal of the isopropylidene groups from 5 and hydrolysis of the ethyl ester yielded the DAH barium salt quantitatively. Copyright (C) 1996 Elsevier Science Ltd
Reactions of monosaccharide derivatives with diazocarbonyl compounds. Reactivity and synthetic applications
作者:Francisco Sarabia García、Gracia María Pedraza Cebrián、Alfonso Heras López、F.Jorge López Herrera
DOI:10.1016/s0040-4020(98)00369-x
日期:1998.6
different stabilized diazocompounds is reported. Studies on the reactivity of the condensation products have been undertaken, finding out novel transfromations of β-oxy-α-diazo carbonyl compounds with sinthetic applications. Thus, a stereoselective Wolff rearrangement provided syn 2-hydroxy-1-methyl compounds, which represent macrolide type structural subunits. On the other hand, rhodium (II) mediated rearrangements