Rearrangements of Cyclobutenones. Electrocyclic Ring Closure and Thermal Ring Expansions of 3-Allenyl- and 3-Alkynyl-2-dienyl-4,4- dimethoxycyclobutenones
作者:Antonio R. Hergueta、Harold W. Moore
DOI:10.1021/jo010919g
日期:2002.2.1
Thermal rearrangements of 2-allenyl- and 2-alkynyl-3-(2-ethenylphenyl)-4,4-dimethoxycyclobutenones were studied. At ambient temperature, the allenyl compounds undergo an electrocyclic cascade to give bicyclo[4.2.0]octadienyl-fused cyclobutenones. These unusual tetracyclic cyclobutenones were shown to be viable synthetic precursors to benzo[a]anthracene-7,12-diones, compounds representing the framework
研究了2-烯基-和2-炔基-3-(2-乙烯基苯基)-4,4-二甲氧基环丁烯酮的热重排。在环境温度下,这些烯基化合物经历一个电环级联反应,生成双环[4.2.0]辛二烯基稠合的环丁烯酮。这些异常的四环环丁烯酮被证明是苯并[a]蒽-7,12-二酮的可行的合成前体,这些化合物代表天然存在的抗生素的安古环素基团的骨架。相反,2-炔基环丁烯酮在环境温度下稳定,但在110摄氏度(甲苯)下容易进行重排,得到先前未知的萘衍生物1,2-二氢-2,2-二甲氧基-1-(3-链烯基)萘[2,1-b]呋喃。