sulfuric acid in chloroform 0.25 h; Ambient temperature;

1: 1) LDA / 1) THF, -25 deg C, 1 h, 2a) THF, -78 deg C, 3 h, 2b) RT, 12 h 2: 87 percent / conc. H2SO4 / CHCl3 / 0.25 h / Ambient temperature View Scheme

1: 1) LDA / 1) THF, -25 deg C, 1 h, 2a) THF, -78 deg C, 3 h, 2b) RT, 12 h 2: 87 percent / conc. H2SO4 / CHCl3 / 0.25 h / Ambient temperature View Scheme