Grignard reagents followed by N-alkylation at position 1 afforded the 1,7,7-trisubstituted hexahydropyrazolo[1,5-a]pyridin-2(1H)-ones, whereas 1,3-dipolar cycloadditions of these dipoles to typical acetylenic and olefinic dipolarophiles gave 4a-substituted 2a,2a1-diazacyclopenta[cd]indene derivatives as the first representatives of a novel heterocyclic system. Regio- and stereoselectivity as well as the mechanism
两个环状甲
亚胺亚胺,7-甲基和7-苯基-2-氧代- Δ 7 -hexahydropyrazolo [1,5-一个]
吡啶-8-鎓-1- IDE,在七个步骤制备来自各市售δ -
酮酸。加入
格氏试剂,然后在位置1进行N-烷基化,得到1,7,7-三取代的六氢
吡唑并[1,5 - a ]
吡啶2-2 (1 H)-一,而这些偶极的1,3-偶极环加成到典型的炔属和烯烃双极性亲和剂,得到4a-取代的2a,2a 1-二氮杂环戊基[ cd] indene衍
生物作为新型杂环系统的第一个代表。使用计算和实验方法评估了区域和立体选择性以及这些[3 + 2]-环加成的机理。通过能量上有利的顺/内过渡态,获得的数据与极性一致的环加成机理相一致。