Regioselective and stereoselective synthesis of tetrahydrofurans from a functionalized allylic silane and an aldehyde via formal [3+2]-cycloaddition reaction

✍ Scribed by Steven R. Angle; Inchang Choi

• Publisher: Elsevier Science
• Year: 2008
• Tongue: French
• Weight: 274 KB
• Volume: 49
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/j.tetlet.2008.08.046

✦ Synopsis

Allylsilanes are known as useful reagents for the stereoselective formation of ring systems. Previous studies have shown that tetrahydrofurans can be constructed via formal [3+2]-cycloadditions of aldehydes and allylsilanes. A new challenge is to understand the intermediate, after a nucleophile attacks a carbonyl activated by the Lewis acid, in which two silyl-protected alkoxy groups with chemical equivalency could undergo formal cycloaddition reaction to afford a disubstituted and/or a trisubstituted tetrahydrofuran.

Preparation of the protected a-hydroxy aldehyde and a functionalized allylic silane is discussed, as well as their formal cycloaddition reaction to form tetrahydrofurans.