Δ14-Vincamine

14,15-Dehydrovincamine

17,18-Didehydrovincamine

(3α,16α)-14,15-Dihydro-17,18-didehydro-14-hydroxyeburnamenine-14α-carboxylic acid methyl ester

(3α,14S,16α)-14,15-Dihydro-17,18-didehydro-14-hydroxyeburnamenine-14-carboxylic acid methyl ester

(3α,14S,16α)-17,18-Didehydro-14,15-dihydro-14β-hydroxyeburnamenine-14-carboxylic acid methyl ester