LANTHANOIDS IN ORGANIC-SYNTHESIS .2. REDUCTION OF A VARIETY OF FUNCTIONAL-GROUPS WITH SAMARIUM DIIODIDE-BASE SYSTEM

The reduction of a variety of functional groups with the new samarium diiodide-base system was investigated. This system reduced rapidly ester, lactone, anhydride, acyl halide, ketone, aldehyde, amide and oxime functionalities to the corresponding reduction products in the presence of protic solvent at room temperature in good yields. Benzoic anhydride was reduced with this system to the aldehyde as well as the alcohol and the carbonyl group of aromatic ketone wad partly reduced into the methylene group. Particularly, similarly to the preceding results of carboxylic acid and nitrile, it is of interest that this system reduced ester, anhydride and amided functionalities which are inert with SmI2. These reductions using KOH or LiNH2 in the addition of H2O proceeded smoothly, and the yields of aromatic carbonyl derivatives was generally superior to those of aliphatic carbonyl derivatives.