1: caesium carbonate / tetrahydrofuran / 0.5 h / 0 °C / Inert atmosphere 2: Oxonereg;; C8H6O4(2-)*Cu(2+) / toluene / 6 h / 60 °C / Molecular sieve; Air atmosphere 3: N-bromosuccinmide; 2,2'-azo-bisisobutyronitrile / tetrachloromethane 4: toluene-4-sulfonic acid / toluene / 1 h / Reflux View Scheme

1: Oxonereg;; C8H6O4(2-)*Cu(2+) / toluene / 7 h / 60 °C / Molecular sieve; Air atmosphere 2: N-bromosuccinmide; 2,2'-azo-bisisobutyronitrile / tetrachloromethane / Reflux View Scheme

<b>Multi-step reaction with 5 steps<br /> </b>1: pyridine / 6 h / 20 &deg;C<br />2: hydrogen bromide; acetic acid / dichloromethane / 3 h / 0 &deg;C<br />3: CuSO_4‵5H₂O; acetic acid; zinc / water / 2.5 h / 0 &deg;C<br />4: methanol; sodium methylate / 4 h / 20 &deg;C<br />5: dipyridinium dichromate; acetic acid / ethyl acetate / 16 h / 20 &deg;C<br /> <br /> &nbsp;

<b>Multi-step reaction with 4 steps<br /> </b>1: hydrogen bromide; acetic acid / dichloromethane / 3 h / 0 &deg;C<br />2: CuSO_4‵5H₂O; acetic acid; zinc / water / 2.5 h / 0 &deg;C<br />3: methanol; sodium methylate / 4 h / 20 &deg;C<br />4: dipyridinium dichromate; acetic acid / ethyl acetate / 16 h / 20 &deg;C<br /> <br /> &nbsp;