Diels-Alder cycloaddittion reactions of enaminothions with nitroalkenes

✍ Scribed by P.D. Baruah; S. Mukherjee; M.P. Mahajan

• Book ID: 104204923
• Publisher: Elsevier Science
• Year: 1990
• Tongue: French
• Weight: 738 KB
• Volume: 46
• Category: Article
• ISSN: 0040-4020
• DOI: 10.1016/s0040-4020(01)89763-5

✦ Synopsis

Diels-Alder cycloaddition reactions of enaminothiones (1) with nitroalkenes (5) result in very good yields (78-90%) of (2R, 3S, 4R) -6-aryl-2-ar$/furyl-3, rl-dihydro-4-dimethylamino-3-nitro-2H-thiopyrans (2) as exclusive stereoisomers. The reactions of 3-N-arylamino-1-phenylpropene-l-thiones (5) with 2 leading to stereospecific formation of (2R,3S.4S)-2-aryl-4-arylamino-3-nitro-6-phenyl-3,4-dihydro-2H-thiopyrans (a) and their conversions to thermodynamically more stable (2R, 3S,4R)-2-aryl-4-arylamino-3-nitro-6-phenyl-3,4-dihydro-2H-thiopyrans (I) is also reported.