Wheel of LAH

Lithium aluminum hydride, LiAlH4 or Li[AlH4] (LAH) is an inorganic compound that is typically a strong reducing agent.


LAH is used especially for the reduction of esters, carboxylic acids, and amides.

A reducing agent may or may not be selective in an organic reaction (chemoselectivity).

The nature of reduction may change depending on the stoichiometric use and/or elevated temperature and/or use of another reagent like a catalyst.

If the product has a new chiral center, stereoisomers may be obtained (stereochemistry).

Since LAH is a hydride donor, it is dangerously reactive toward water, releasing Hydrogen gas.



Wheel of LAH: Click/tap to enlarge the image

Substrates -> Products (on the infographic):

  1. Esters -> 10 alcohols
  2. Carboxylic acids -> 10 alcohols
  3. Acid chlorides -> 10 alcohols
  4. Aldehydes -> 10 alcohols
  5. Ketones -> 20 alcohols
  6. Epoxides -> 20/30 alcohols
  7. Haloalkanes -> Alkanes
  8. Nitriles -> 10 amines
  9. Amides -> 10 amines
  10. Azides -> 10 amines
  11. Epoxycyclohexanes -> Axial alcohols
  12. α, β-unsaturated ketones -> Allylic alcohols

When epoxides are reduced using LAH, the reagent attacks the less hindered end of the epoxide (regiochemistry), usually producing a 20 or 30 alcohol.

Looking for more on LAH? Click HERE!

What other wheel(s) 🎡 of organic reactions would you like to see ❓Questions❓ Let Chemaficionado know in the comments below or at mychemistryhomework@gmail.com❗

References:

(1)    Brown, C.; Ford, M. Higher Level Chemistry, 2nd ed.; Pearson Education: Harlow, Essex, 2014.

(2)    Ncert. Chemistry : Textbook for Class XI - Part.I; National Council Of Educational Research And Training: New Delhi.

(3)    Graham, T. W.; Fryhle, C. B.; Snyder, S. A. Organic Chemistry.; Hoboken, Nj John Wiley Et Sons, Inc, 2016.

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