OXIDATION REACTION Indah Purnama Sary

Function & Application in Biology and Pharmacy?? Oxidation reaction What?? How ?? Function & Application in Biology and Pharmacy?? FGs undergo ??

WHAT Oxidation: increasing the oxygen content or decreasing the hydrogen content of an organic molecule A general symbol for oxidation is [O] Oxidation can also be defined as a reaction that increases the content of any element more electronegative than carbon

Oxidation States in Carbon Similar to formal charges Calculate oxidation states of C by: -1 = a bond to H/less electronegative +1= a bond to O, N, F, Cl, Br 0 = a bond to C Example: Assign oxidation states to the carbon atoms of methanol (CH3OH), formaldehyde (HCHO), and formic acid (HCO2H), carbon dioxide (CO2) and methane (CH4)and arrange these compounds in order of increasing oxidation state

Oxidation Level nn

Determine oxidation level for each carbon in compounds above

Mechanism of Chromate Oxidation Also called Jones oxidation convert 2°Alcohol to Ketone

Mechanism of Chromate Oxidation Step 1: A chromate ester is formed from the alcohol hydroxyl Step 2: An elimination reaction occurs by removal of a hydrogen atom from the alcohol carbon and departure of the chromium group with a pair of electrons

What about 1° Alcohol ?

Hydroboration: Synthesis of Alkylboranes Alcohols from Alkenes through Hydroboration-Oxidation: Anti-Markovnikov Syn Hydration The reaction leads to syn and anti-Markovnikov addition of water to alkenes Hydroboration: Synthesis of Alkylboranes The elements of hydrogen and boron are added across the double bond In practice, a borane complex with the solvent tetrahydrofuran (THF) is often used

Boron becomes attached to the least substituted carbon of the double bond The boron and hydride add with syn stereochemistry

Oxidation and Hydrolysis of Alkylboranes Oxidation and hydrolysis to the alcohol takes place with retention of stereochemistry at the carbon bonded to boron