Tandem Beckmann and Huisgen–White rearrangement as an alternative to the Baeyer–Villiger oxidation of the bicyclo[3.3.1]nonane system: first asymmetric synthesis of (–)-dihydropalustramic acid. X-Ray molecular structure of 2β-ethyl-9-phenylsulfonyl-9-azabicyclo[3.3.1]nonan-3-one
作者:Osamu Muraoka、Bao-Zhong Zheng、Kazuhito Okumura、Genzoh Tanabe、Takefumi Momose、Conrad Hans Eugster
DOI:10.1039/p19960001567
日期:——
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。