Simple prediction of cycloaddition orientation: I—Diels-alder reactions

✍ Scribed by O. Eisentein; J.M. Lefour; Nguyên Trong Anh; R.F. Hudson

• Book ID: 104207254
• Publisher: Elsevier Science
• Year: 1977
• Tongue: French
• Weight: 637 KB
• Volume: 33
• Category: Article
• ISSN: 0040-4020
• DOI: 10.1016/s0040-4020(77)80010-0

✦ Synopsis

Application of the "hard and soft" concept to the Woodward-Katz model allows simple and accurate prediction of the structure of the major adduct in Diels-Alder reactions. About 100 examples have been examined. Agreement with experimental results is excellent: therefore, the doubts expressed by Houk et al. 3~ are groundless.

Two special cases deserve mention. First, for compounds with heteroatoms at reactive sites, it is necessary to introduce explicitly the overlap integrals in the perturbational treatment. Second, in the reactions between electron-poor dienes and nitrosobenzene derivatives, the adjacent lone pairs on N and O play an important role.

(1) OEt CO2Me B B 4 (2) Me CO2Me B B 4 (3) Me CN B B 12 (4) Me Ph B B 12 (5) Me CHO B B 12 (6) Ph CN B B 12 (7) Ph CO2Me B B 4 (8) CI CO2Me B B 4 (9) CN CO2Me B B 4