Formation of Cyclobutylidenepyrazolines by Methanolysis of 6-(2,3,3-Trifluorocyclobutenyl)-4,5-diazaspiro[2.4]hept-4-ene
作者:Ekaterina V. Guseva、Nikolay V. Volchkov、Yury V. Tomilov、Boris B. Averkiev、Oleg M. Nefedov
DOI:10.1002/ejoc.200390084
日期:2003.2
The reaction of 6-(2,3,3-trifluorocyclobutenyl)-4,5-diazaspiro[2.4]hept-4-ene with NaOMe in MeOH results in a mixture of isomeric (6E)- and (6Z)-6-(2-fluoro-3,3-dimethoxycyclobutylidene)-4,5-diazaspiro[2.4]hept-4-ene due to the formal substitution of methoxy groups for two geminal fluorine atoms. Both of the isomers selectively add acetyl chloride at the azo-olefin unit to give 4-acetyl-6-(1-chloro-2-fluoro-3
6-(2,3,3-三氟环丁烯基)-4,5-二氮杂螺[2.4]庚-4-烯与NaOMe在MeOH中的反应产生异构体(6E)-和(6Z)-6-( 2-氟-3,3-二甲氧基环亚丁基)-4,5-二氮杂螺[2.4]庚-4-烯由于甲氧基对两个孪生氟原子的形式取代。两种异构体都选择性地在偶氮烯烃单元添加乙酰氯,得到 4-乙酰基-6-(1-氯-2-氟-3,3-二甲氧基环丁基)-4,5-二氮杂螺[2.4]hept-4-烯作为反式异构体,产率超过 95%。(© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2003)