Studies on the Radical Cyclization of 3-Oxopropanenitriles and Alkenes with Cerium(IV) Ammonium Nitrate in Ether Solvents

✍ Scribed by Mehmet Yılmaz

• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: German
• Weight: 155 KB
• Volume: 94
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.201000440

✦ Synopsis

The radical cyclization of 3-oxopropanenitriles 1a -1e and alkenes 2a -2g with cerium(IV) ammonium nitrate (CAN) in ether solvents was investigated (Tables 1 and2). In the optimization study, 1,3-dioxolane, 1,4-dioxane, 1,2-dimethoxyethane, Et 2 O, and THF were used as ether-based solvents, and the latter was found to be the most effective solvent in radical cyclizations mediated by cerium(IV). This system (cerium(IV)/THF) was applied to cyclizations of various 3-oxopropanenitriles and 1,3-dicarbonyl compounds with alkenes resulting in the formation of 4,5-dihydrofurans in high yields (Table 2 andScheme 2). The results of the cerium(IV)/THF radical cyclization were compared with those obtained with manganese(III) acetate/AcOH; the cerium(IV)/THF system turned out to be much more efficient.