Chemical and Pharmaceutical Bulletin · 2000 · 33 citations · 0 references
Natural SciencesChemistryMedicinal ChemistryDrug DiscoveryOrganic ChemistrySynthetic Medicinal ChemistryHeterocycle SynthesisHeterocyclic ChemistryOrganic SynthesisAlkaloid Skeleton FormationElectrocyclic ReactionsEnantioselective SynthesisIndole ChemistryIndole SynthesisNatural Product Total SynthesisTotal Synthesis-derived Analogues
A new type of beta-carboline nucleus, N-methoxymethyl-4-methyl-beta-carboline (4) was synthesized by thermal electrocyclic reaction of a 1-azahexatriene system, involving the indole 2,3-bond. The key compound N-methoxymethyl-1-methoxycarbonyl-4-methyl-beta-carboline (2) was then prepared in a four-step sequence. The total synthesis of oxopropaline G (1e) was achieved from this key compound in four steps. Furthermore, the enantioselective total syntheses of (+)-oxopropaline D (1c) and its enantiomer were also achieved by application of the Sharpless oxidation-procedure in nine steps from 2.