... The Diels-Alder chemistry was equally efficient in the construction of the corresponding ketone 15. Smith! ... 1979,101,7001. Sugasawa, S.; Yamada, S. I.; Harahashi, M. J. Pharm. ... (18) Fleming, I. Frontier Orbitals and Organic Chemical Reactions; Wiley: New York, 1976; p 86. ...