Lewis acid mediated thienium cation diels-alder reaction: A new method for regio- and stereoselective functionalization of 1,3-dienes

✍ Scribed by Kaoru Fuji; Subhash P. Khanapure; Manabu Node; Takeo Kawabata; Akichika Ito

• Publisher: Elsevier Science
• Year: 1985
• Tongue: French
• Weight: 189 KB
• Volume: 26
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)89135-2

✦ Synopsis

Under the influence of aluminum chloride the B-ethylthionitroolefin results in the formation of the thienium cation, which reacts with a variety of 1,3-dienes in the Diels-Alder sense. The cleavage of the resulting ring provides in one pot the 1,4-functionalized olefins in regio-and stereoselective manner.

The electrophilic addition reaction of 1,3-diene with an electrophile (XY) may lead to the formation of three types of products 1, 2, and 3 as shown in .

-. Scheme 1.

Generally, 1,2-addition is the predominant mode in electrophilic additions to 1,3-dienes. 1 Moreover, steroselective formation of either isomer