| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain the subject compound in high yield by cyclization of a specific compound having a halogen or sulfonic ester group. SOLUTION: This compound of formula II is obtained by cyclization of a compound of formula I [R<1> is H, a (substituted) 1-8C alkyl, p-cyanophenyl, p-carbamoyl or the like; R<2> is H, a (substituted) 2-8C alkenyl or the like; R<3> is H, ClCO, formyl, benzyloxycarbonyl or the like; X is a halogen or sulfonic ester group] pref. using a base (e.g. sodium hydroxide) at -20 to 100 deg.C. By the way, the compound of formula I is prepared by reaction of a compound of formula III pref. in a solvent such as toluene or methyl-isobutyl ketone in the presence of a base (e.g. mesyl chloride).</p> |
