The transformation of the ‘fork head ketone’ 3b into the corresponding bicyclic lactone 13 via the Beckmann followed by the Huisgen–White rearrangement is described. Application of the method to a homochiral 2-etyl-substituted bicyclic ketone (+)-3dα gave efficiently (–)-dihydropalustramic acid (–)-2a, a degradation product from the alkaloid palustrine 1, in good optical yield.
描述了通过贝克曼将“叉头酮” 3b转变为相应的双环内酯13 ,然后进行了惠斯根-怀特重排。该方法在同手性2-乙基取代的双环酮(+)-3dα上的应用可有效地产生(-)-二氢palustramic酸(-)-2a,这是
生物碱palustrine 1的降解产物,具有良好的光学收率。