REDUCTION OF WEINREB AMIDE TO ALDEHYDE

Using LAH

Procedure

1.    Dissolve Weinreb Amide in Et₂O.  Stir.  Cool to 0 ^oC

2.    Add LAH/Et₂O [1]

3.    Stir the mixture at 0 ^oC for 1 hr [2]

4.    Quench slowly w/sat aq. KHSO₄ [3]

5.    Warm to R.T.  Stir for 30 min

6.    Add 1N HCl and stir for 2 hrs [4] ® separate

7.    Wash organic layer w/sat NaHCO₃ then water and brine

8.    Dry w/MgSO₄.  Filter

9.    Concentrate in vacuo  [5]® crude as colorless liquid

10.           NMR w/CDCl₃.  Yield >95% [6]