Et3Si[B(C6F5)4] in toluene T=-78°C; Mukaiyama aldol reaction; 1 h;

2-chloro-1,3,2-dioxaborolane; N-ethyl-N,N-diisopropylamine 1.) CH2Cl2, -78 deg C, 30 min. 2.) -78 to -15 deg C; Yield given. Multistep reaction. Yields of byproduct given;