CH3 CH3 H3C—CH H3CCH NH n-CaHgLi_THF NLi n-C4H10 H3CCH H3GCH CH3 CH3 pKa 40 LDA 50 C H C H 3 N H C H C H 3 H 3 C + n-C 4 H 9 Li C H C H 3 N Li CHCH3 H 3 C H 3 C H 3 C + n-C 4 H10 THF p Ka LDA 40 50