Jy. Merour et al., HETERODIENE CYCLOADDITIONS - SYNTHESIS AND OXIDATION OF PYRANO[3,2-B]INDOLES INTO SPIRO DERIVATIVES, Tetrahedron, 53(3), 1997, pp. 987-1002
1-Acetyl-2-benzylidene-2,3-dihydroindol-3-ones reacted with vinyl othe
rs and vinyl thioethers to afford substituted pyrano[3,2-b]indoles; th
ese compounds were oxidized, using Jones reagent, to spirolactones or
to oxo acetals with m-CPBA in the presence of baron trifluoride. Copyr
ight (C) 1996 Elsevier Science Ltd