| 摘要 |
<p>The cyclisation of compounds of the formula: (I) wherein: (a) R1 is H or alkyl of one to four carbon atoms; (b) R2 is H or alkyl of one to four carbon atoms, with the proviso that R1 is H when R2 is alkyl, and with the proviso that R2 is H when R1 is alkyl; (c) R3 is a suitable leaving group selected from the group consisting of hydroxy, alkoxy of one to four carbons, alkoxyalkoxy of two to four carbons, acyloxy of one to about seven carbon atoms, and trialkylsilyloxy of less than fifteen carbons; (d) R4 is H, hydrocarbyl of one to fourteen carbons, carboxyacyl of two to twelve carbons, trialkylsilyl of less than fifteen carbons, or heterocyclic of five to seven atoms and four to six carbons; and (e) R5(1) and R5(2) are each H, alkyl of one to eight carbons, or an optionally esterified or etherified hydroxy group selected from the group consisting of hydroxy, alkoxy of one to four carbons, alkoxyalkoxy of two to four carbons, carboxyacyloxy of one to seven carbons, trialkylsilyloxy of one to fifteen carbons, cycloalkoxy of four to eight carbons, or unsubstituted heterocyclic ether of five to seven members, with the proviso that at least one of R5(1) and R5(2) is hydrogen, leads to novel and biologically active compounds of the following formulae: II III "para" "ortho" having R1 through R5(1) and R5(2) as defined above, with R7 being alkyl of from about one to about four carbon atoms.</p> |
