Indole Alkaloids. XVII. Five Dihydroindole Alkaloids from Aspidosperma Verbascifolium

A study of Aspidosperma verbascifolium has led to the isolation of four known dihydroindole alkaloids: kopsanone [I], kopsanol [II], 3'-epikopsanol [III], 10-oxo-3'-epikopsanol [IV] and a new natural product: Nα-formylkopsanol [VII].