pyridine; chromium(VI) oxide in dichloromethane

<b>Multi-step reaction with 3 steps<br /> </b>1: diethyl ether<br />2: diethyl ether<br />3: (i) aq. H₂SO₄, I₂, AcOH, (ii) /BRN= 4720968/, Et₂O<br /> <br /> &nbsp;