(i) Et3N, ZnCl2, ClSiMe3, (ii) /BRN= 605462/, (iii) aq. HCl; Multistep reaction;

1: With sodium hydride in tetrahydrofuran; N,N-dimethyl-formamide; mineral oil T=0°C; 1.41667 h; 2: With dimethyl sulfate in tetrahydrofuran; N,N-dimethyl-formamide; mineral oil T=20°C; 16 h;

1: With acetyl chloride in cyclohexane T=0°C; 0.5 h; 2: With toluene-4-sulfonic acid in methanol; cyclohexane T=81°C;

1) THF, 1 h, reflux, 2) 30 min, reflux; Yield given. Multistep reaction;

in dimethyl sulfoxide