1: (-)-1,2,14,15-tetradehydroaspidospermidine With n-butyllithium; diisopropylamine in tetrahydrofuran; hexane T=-78 - 0°C; 1 h; Inert atmosphere; 2: methoxycarbonyl cyanide in tetrahydrofuran; hexane T=-78°C; 1 h; Inert atmosphere;