in tetrahydrofuran 4 h; Ambient temperature;

1: 63 percent / p-toluenesulfonic acid / benzene / Heating 2: 60 percent / tetrahydrofuran / 4 h / Ambient temperature View Scheme

magnesium 1.) THF, 2.) THF; Yield given. Multistep reaction;

in deuterated toluene Mixing equimolar amts. of the chiral diol and TiCl2(O-iPr)2 in C7D8.; Not isolated, NMR, addn. of molecular sieves (4A) shifts equilibrium to the side of chiral Ti-complex.;