A synthesis of the Prelog-Djerassi lactone [(+)-1] has been accomplished in three isolations and 57% overall yield from the known vinyl ortho ester 2. A Rh(I)-catalyzed asymmetric hydroformylation/crotylation tandem sequence has been developed and used to set the C2-C4 stereochemistry. A Rh(I)-catalyzed asymmetric hydrogenation was employed to set the C6 sterechemistry, resulting in an unusually short and efficient enantioselective synthesis of this touchstone molecule from achiral starting material.
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http://dx.doi.org/10.1021/ol3008765 | DOI Listing |
J Org Chem
January 2015
†Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States.
Four different Rh-catalyzed asymmetric hydroformylation (AHF) tandem reactions have been developed in the context of the total syntheses of (+)-patulolide C, (-)-pyrenophorol, (+)-decarestrictine L, and (+)-Prelog-Djerassi lactone. A total synthesis of (+)-patulolide C has been accomplished in three steps utilizing a Rh(I)-catalyzed Z-selective anti-Markovnikov hydroacetoxylation of a known alkyne to give a Z-enol acetate with excellent selectivity. An AHF/intramolecular Wittig olefination cascade was utilized to set the C4-hydroxyl stereochemistry, E-olefin geometry, and form the macrolactone.
View Article and Find Full Text PDFOrg Lett
May 2012
Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706-1322, United States.
A synthesis of the Prelog-Djerassi lactone [(+)-1] has been accomplished in three isolations and 57% overall yield from the known vinyl ortho ester 2. A Rh(I)-catalyzed asymmetric hydroformylation/crotylation tandem sequence has been developed and used to set the C2-C4 stereochemistry. A Rh(I)-catalyzed asymmetric hydrogenation was employed to set the C6 sterechemistry, resulting in an unusually short and efficient enantioselective synthesis of this touchstone molecule from achiral starting material.
View Article and Find Full Text PDFOrg Lett
November 2001
Institut de Chimie des Substances Naturelles 91198 Gif sur Yvette, France.
[reaction--see text] A one-step catalytic asymmetric access to alpha,beta unsaturated delta-lactones is described, using a vinylogous Mukaiyama-aldol reaction between a gamma-substituted dienolate and various aldehydes in the presence of Carreira catalyst CuF.(S)-tolBinap. This methodology has been further applied to a straightforward access to the Prelog-Djerassi lactone.
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