Red-Al, Sodium bis(2-methoxyethoxy)aluminumhydride
Sodium bis(2-methoxyethoxy)aluminium hydride (Red-Al) is comparable to LiAlH4. The most important differences are found in the reduction of nitriles, which are selectively reduced to aldehydes, and in the reduction of aromatic aldehydes.
The main advantages of the reagent compared with lithium aluminium hydride are the insensitivity against oxygen and the good solubility in organic solvents. Thus, a 70%-solution in toluol is commercially available.
Recent Literature
γ-Hydroxy-α,β-acetylenic esters are used as precursors for the preparation of γ-hydroxy-α,β-alkenoic esters
by means of trans-selective additions of two hydrogen atoms or one hydrogen atom
and one iodine atom across the triple bonds. These methods allow the preparation
of β-substituted and α,β-disubstituted alkenoic esters in highly stereoselective
manners.
C. T. Meta, K. Koide, Org. Lett., 2004, 6, 1785-1787.
Red-Al is an efficient chelation-controlled reducing reagent for acyclic
acetal-protected R-hydroxy ketones. Typically, high diastereomeric ratios
and yields can be achieved for the synthesis of 1,2-anti-diols.
N. Bajwa, M. P. Jennings, J. Org. Chem., 2008,
73, 3638-3641.