boric acid trimethyl ester; dimethylsulfide borane complex in tetrahydrofuran T=20°C; Reduction; 24 h;

boric acid trimethyl ester; dimethylsulfide borane complex; toluene-4-sulfonic acid 1.) THF, r.t., 24 h, 2.) CH2Cl2, r.t., 24 h; Yield given. Multistep reaction;