A New Enantioselective Total Synthesis of Natural Vincamine via an Intramolecular Mannich Reaction of an Silyl Enol Ether

W Oppolzer, H Hauth, P Pfäffli…

文献索引：Oppolzer; Hauth; Pfaffli; Wenger Helvetica Chimica Acta, 1977 , vol. 60, # 5 p. 1801 - 1810

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被引用次数: 38

摘要

Abstract Natural Vincamine (1) has been synthesized in an enantioselective manner starting from the ethylpentenal 7. In the key step a mixture of the diastereoisomeric racemates, 14 and 15, was directly obtained from the silyl enol ether 11 and the dihydro-β-carboline 12 by the way of an intramolecular Mannich reaction of the intermediate 13 (Scheme 4). The undesired stereoisomers, 14 and 15b, were recycled to 15a using the related reversible ...