| 摘要 |
<p>NEW MATERIAL:A 2-methyl-3-hydroxymethyl-4-alkoxycarbonylmethyl-5- alkoxycarbonyl-3,4-dihydro-2H-pyran expressed by formula I (R<1> and R<2> represent 1-5C alkyl). USE:A precursor for synthesis of (-)-alkylenolate exhibiting antiviral activity. PREPARATION:A cyclic diether derivative expressed by formula II is subjected to removal of acetonide to form a crude diol derivative, which is then protected in its primary hydroxy group to form a novel intermediate expressed by formula III (X represents protecting group). This intermediate is reacted with a propiolic acid alkyl ester and treated with a brominating agent to afford a novel intermediate expressed by formula IV. After cyclizing this intermediate, double bond is introduced into the ring and the above-mentioned hydroxy-protecting group is eliminated.</p> |
