Design of a cyclopropyl quinone methide reductive alkylating agent. 2.
A cyclopropyl quinone methide is formed by elimination of a leaving group from an appropriately functionalized hydroquinone. The presence of a carbon spacer results in the formation of a fused ring rather than the classic methide species. Discussed herein is cyclopropyl quinone methide formation from a pyrido[1,2-a]indole ring system. Both nucleophilic and electrophilic attack on the fused cyclopropane ring results in pyrido[1,2-a]indole and azepino[1,2-a]indole products. The stereoelectronic effect plays less a role in the relatively flexible pyrido[1,2-a]indole system compared to its role in the pyrrolo[1,2-a]-indole system. A 13C label on the fused cyclopropane ring permitted the rapid identification of complex rearrangement products observed in this study.
Khdour
Omar
O
Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604, USA.
Ouyang
Anlong
A
Skibo
Edward B
EB