The preferentially formed (−)-sparteine complex from 1-lithio-2-butenyl N,N-diisopropylcarbamate has ( S)-configuration at the metal bearing carbon atom, in contrary to our previous assumption. Transmetallation with titanium tetraisopropoxide and the carboxylation proceed with inversion. The addition of aldehydes occurs in a anti-S E′-process. The enantioselective synthesis of homoaldol adducts and some corresponding γ-lactones is reported.