1: aq. K2CO3 / methanol / Ambient temperature 2: 88.9 percent / 80percent aq. CF3COOH / 3 h / Ambient temperature 3: 2.) p-toluenesulfonic acid / 1.) toluene, reflux, 30 min, 2.) toluene, reflux, 3 h View Scheme

1: aq. K2CO3 / methanol / Ambient temperature 2: 88.9 percent / 80percent aq. CF3COOH / 3 h / Ambient temperature View Scheme

<b>Multi-step reaction with 2 steps<br /> </b>1: O₂, (EtO)3P, tBuONa / dimethylformamide / 2 h / -40 &deg;C<br />2: 98.1 percent / DMAP / CH₂Cl₂ / 4 h / 40 &deg;C<br /> <br /> &nbsp;