A convenient preparation of 3,4-bismethylenecyclopentanone ethylene ketal, a new valuable diene for Diels-Alder reaction, designed to produce functionalized [6.5] ring systems, is described. A formal synthesis of gibberellic acd GA3 using as starting materials two cycloadducts derived from the title compound demonstrates the value and the applicability of this methodology for the construction of functionalized
描述了一种方便的制备3,4-双亚甲基环戊酮乙烯缩酮的方法,该缩酮是一种用于Diels-Alder反应的新型有价值的二烯,旨在生产功能化的[6.5]环系。使用两个衍生自标题化合物的环加合物作为起始原料,正式合成了赤霉素acd GA 3,证明了该方法的价值和对功能化氢化茚体系构建的适用性。
1,3-Asymmetric induction in the intramolecular [2+2] cycloaddition of alkene-keteniminium salts. Synthesis of (+)-gibberellic acid key intermediate
作者:Pil-Jong Shim、Hee-Doo Kim
DOI:10.1016/s0040-4039(98)02228-x
日期:1998.12
Optically active bicyclo[4.2.0]octan-7-ones were synthesized by stereoselective intramolecular [2+2] cycloaddition of alkene-keteniminium salt derived from L-glutamic acid, based on 1,3-asymmetric induction. Synthetic application toward (+)-gibberellic acid key intermediate was also described.