| 摘要 |
<p>PT--82039 A 4,6-Dioxo 10-propyl 4H,6H-pyrano(3,2-g) chromene 2,8-dicarboxylic acid is made by (a) reacting 2-propyl resorcinol with sodium hydride in DMSO; (b) reacting the prod. with methyl 2,3-epoxy succinate; (c) converting the prod. to O,O'-di(a,b-dimethoxycarbonyl 6-hydroxy)ethyl 2-propyl resorcinol; (d) dehydrating with p-toluene sulphonyl chloride to give O,O'-di(a,b-dimethoxy carbonyl)ethyleno -2-propyl resorcinol; (e) hydrolysing this; and (f) cyclising with polyphosphoric acid to give the required prod.</p> |
