The formal dipolar behaviour of furan-2,3-diones is illustrated by their reaction with ethyl glyoxylate under Lewis basic activation uniquely, giving access to isotetronic derivatives. The Janus-type nature of the activated species, both nucleophilic and electrophilic is revealed by ring-opening of the starting ketolactone. An unexpected reversible side-reaction was identified by in situ monitoring
呋喃-2,3-二酮的形式偶极行为可以通过在Lewis碱性活化下与
乙醛酸乙酯的反应来唯一说明,从而获得了等电子衍
生物。通过起始酮内酯的开环揭示了亲核和亲电子的活化物种的Janus型性质。通过原位监测发现意外的可逆反应。