Synthetic studies toward the pyran core and the amide side chain of psymberin

✍ Scribed by Hugo Lachance; Olivier Marion; Dennis G. Hall

• Book ID: 104095698
• Publisher: Elsevier Science
• Year: 2008
• Tongue: French
• Weight: 205 KB
• Volume: 49
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/j.tetlet.2008.07.170

✦ Synopsis

A synthetic approach to the polysubstituted pyran core and amide side chain of psymberin (irciniastatin A) using stereoselective organoboron methodology is described. An advanced oxyranyl pyran intermediate was prepared using a catalytic enantioselective and diastereoselective three-component reaction involving first an inverse electron-demand hetero [4+2] cycloaddition between 3-boronoacrolein pinacolate and 1-ethoxy-2-methylpropene, followed by an allylboration of ethyl glyoxylate. The amide side chain was prepared highly efficiently using the first example of a doubly diastereoselective allylboration of a chiral a-alkoxy aldehyde under the Lewis acid-catalyzed reaction manifold.