中文名称 | 英文名称 | CAS号 | 化学式 | 分子量 |
---|---|---|---|---|
—— | methyl 3-O-benzyl-4,6-O-benzylidene-2-deoxy-2-C-(2-methoxycarbonylpropyl)-α-D-altroside | 131529-28-7 | C26H32O7 | 456.536 |
Treatment of methyl 2,3-anhydro-4,6-O-benzylidene-α-D-alloside with the anion derived from trimethyl(prop-1-ynyl)silane, allylmagnesium chloride or isobutenylmagnesium chloride introduces a three- or four- carbon substituent at C2 of the sugar. In each case, a hydroboration-oxidation sequence helps convert the centre of unsaturation in the new substituent into a carboxylic acid residue. Subsequent manipulations allow the introduction ofanother carbon at C6 of the sugar to give a highly functionalized precursor to the C1-C9 fragment of tylonolide, the aglycon of the antibiotic tylosin. Attempts at the introduction of an axial methyl group at C4 of the extended sugar also described.