Generation Of Acyclic Chiral Building Blocks Containing A Quaternary Stereocenter. Formal Synthesis Of Alkaloids Of The Leuconolamleuconoxine-Mersicarpine Group

The stereocontrolled dialkylation at the carbonyl a-position of simple phenylglycinol-derived oxazolopiperidone lactams generates chiral scaffolds bearing a quaternary stereocenter, which are converted to acyclic quaternary stereocenter-containing chiral building blocks, such as 2,2-disubstituted 5-aminopentanols and 4,4-disubstituted O-protected 5-hydroxypentanoic acids and 5-hydroxypentanenitriles. The enantioselective synthesis of Kerr's intermediate, an advanced synthetic precursor of the alkaloids of the leuconolam-leuconoxine-mersicarpine group, is reported from one of these aminopentanols. (C) 2020 Elsevier Ltd. All rights reserved.