... Intramolecular Diels-Alder Reactions of 4H-Furo[3,4-b]indoles. New Syntheses of Benzo[a Jcarbazoles and Benzo[c]carbazoles Gordon W. Gribble,' Richard A. Silva, and Mark G. Saulnier Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755 ... aHooH 602Ph ' THF W/O RD/O 3 4 Page 3. ... The solid was Page 14. 742 GRIBBLE, SILVA, AND SAULNIER washed with CHC13, and the filtrate was dried (K2CO3). concentrated in vacuo, ...