tert.-butyl lithium; magnesium bromide multistep reaction, 1) cyclopentane, CH2Cl2, ether, toluene, -80 deg C to -20 deg C, 3 h, 2) cyclopentane, CH2Cl2, ether, toluene, -50 deg C to -30 deg C, 2 h; Product distribution;

N,N-dibenzylphenylalaninal 1) THF, petrolether, -105 deg C then -85 deg C, 1.5 h, 2) THF, petrolether, 3 h, -105 deg C; Yield given. Multistep reaction. Yields of byproduct given;

multistep reaction; Product distribution;