Synthetic transformations of higher terpenoids: V. 2-methyl-4,5-dioxo-3-ethoxycarbonyl-4,5-dihydroindole, a new dienophile. Synthesis of indoloterpenes from levopimaric acid
Sv. Chernov et al., Synthetic transformations of higher terpenoids: V. 2-methyl-4,5-dioxo-3-ethoxycarbonyl-4,5-dihydroindole, a new dienophile. Synthesis of indoloterpenes from levopimaric acid, RUSS J ORG, 36(11), 2000, pp. 1623-1633
2-Methyl-4,5-dioxo-3-ethoxycarbonyl-4,5-dihydroindol is an active dienophil
e that via [4+2]-cycloaddition to the levopimaric acid and to the cyclopent
adiene affords indole alkaloids of new structural types.