1: N-(triisopropylsilyl)-N-(tert-butyloxycarbonyl)benzylamine With sec.-butyllithium; (-)-sparteine in diethyl ether; cyclohexane T=-78°C; 3 h; 2: carbon dioxide in diethyl ether; cyclohexane 0.333333 h;

tetrabutyl ammonium fluoride 0.166667 h; Product distribution;