Samarium(<scp>II</scp>) iodide promoted reductive fragmentation of γ-halo carbonyl compounds: application to the enantiospecific synthesis of (–)-oudemansin A
The reductive regioselective bond-cleavage reaction of γ-halo carbonyl compounds with samarium(II) iodide is developed and its utilisation in the enantiospecific synthesis of (–)-oudemansin A is described.
The first asymmetric catalytic synthesis of (-)-oudemanisin A 1a and its diastereomer 1b has been achieved. The key steps of our strategy involved the asymmetric alkynylation of an unsaturated aliphatic aldehyde catalyzed by Trost's ProPhenol ligand, chemoselective oxidation of the olefinic diol, base induced ring opening of the lactone, and acylation-alkylation of the ester. (C) 2017 Elsevier Ltd. All rights reserved.
WITTMAN, MARK D.;KALLMERTEN, JAMES, J. ORG. CHEM., 52,(1987) N 19, 4303-4307