Highly enantiomerically enriched (R)-incrustoporin was enantioselectively synthesized in 43.6% overall yield starting from 4-iodotoluene. The key steps of the synthesis included the asymmetric hydrogenation of 1-(p-tolyl)-1-pentyn-3-one catalyzed by a non-racemic Ru(II) complex and the Pd-catalyzed cyclocarbonylation of so-obtained highly enantiomerically enriched 1-(p-tolyl)-1-pentyn-3-ol. This Pd-catalyzed reaction, whose stereochemical outcome was previously unknown, proceeded with retention of configuration and 2.5% or less racemization. The enantiomeric purities of (R)-1-(p-tolyl)-1-pentyn-3-ol and (R)-incrustoporin were evaluated by HPLC analysis on a Chiralcel OJ column as well as by performing the H-1 NMR spectra of these compounds in a D2O solution which was saturated with alpha- or beta-cyclodextrin, respectively. (C) 1999 Elsevier Science Ltd. All rights reserved.
|Autori:||Rossi, Renzo; Bellina, Fabio; Biagetti, M.; Mannina, L.|
|Titolo:||Enantioselective synthesis of (R)-incrustoporin, an antibiotic isolated from Incrustoporia carneola|
|Anno del prodotto:||1999|
|Digital Object Identifier (DOI):||10.1016/S0957-4166(99)00085-3|
|Appare nelle tipologie:||1.1 Articolo in rivista|