The enantioselective alkylation of the “fork head ketone” (1) followed by the Norrish Type I photo-cleavage provided the short enantioselective synthesis of (−)-indolizidine 223AB (4).
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.