CrO3 in anhydrous medium is used as the oxidising agent
for the isolation of aldehydes 3
2
CrO
R H
R
C
OH
CHO

A better  reagent for oxidation of primary alcohols to aldehydes in
good yield is pyridinium chlorochromate (PCC), a complex of
chromium trioxide with pyridine and HCl 3
2
3
PCC
O
CH
CH
CH
H
CH
CH
O
CH
CH
CH








Secondary alcohols are oxidised to ketones by chromic anhyride
(CrO3) Tertiary alcohols do not undergo oxidation reaction