Wijdeven MA (Wijdeven, Marloes A.), Wijtmans R (Wijtmans, Roel), van
den Berg RJF (van den Berg, Rutger J. F.), Noorduin W (Noorduin, Wim),
Schoemaker HE (Schoemaker, Hans E.), Sonke T (Sonke, Theo), van Delft
FL (van Delft, Floris L.), Blaauw RH (Blaauw, Richard H.), Fitch RW
(Fitch, Richard W.), Spande TF (Spande, Thomas F.), Daly JW (Daly, John
W.), Rutjes FPJT (Rutjes, Floris P. J. T.)
N,N-Acetals as
N-acyliminium ion precursors: Synthesis and absolute stereochemistry of
epiquinamide
ORGANIC LETTERS Volume: 10 Issue:
18 Pages: 4001-4003 Published: SEP
18 2008
Abstract: A stereoselective
synthesis of (+)-epiquinamide is presented in combination with
determination of the absolute configuration of the natural product. Key
steps in the sequence involved chemoenzymatic formation of an
enantiomerically pure cyanohydrin, reductive cyclization to the
corresponding cyclic N,N-acetal, and subsequent conversion into a
suitable N-acyliminium ion precursor to enable construction of the
second ring.