Three-component reductive alkylation of 2-hydroxy-1, 4-naphthoquinones with lactols

Although it is possible to reduce a carboxylic acid to an aldehyde, strong reducing agents, like lithium aluminum hydride (LAH), prohibit a controlled reduction, instead causing the generated aldehyde to instantly over-reduce to a primary alcohol.
Reducing carboxylic acid derivatives like acyl chlorides (RCOCl), esters (RCO2R′), and nitriles (RCN) using milder aluminum hydride agents like lithium tri-tert-butoxyaluminum hydride [LiAlH(O-t-Bu)3] and diisobutylaluminum hydride [DIBAL-H]...

Reduction is a simple strategy to convert a carbonyl group to a hydroxyl group. The three major pathways to reduce carbonyls to alcohols are catalytic hydrogenation, hydride reduction, and borane reduction.
Catalytic hydrogenation is similar to the reduction of an alkene or alkyne by adding H2 across the pi bond in the presence of transition metal catalysts like Raney Ni, Pd–C, Pt, or Ru. Aldehydes and ketones can be reduced by this method, often under mild to moderate heat (25–100°C) and...

Acid halides are reduced to alcohols in the presence of a strong reducing agent like lithium aluminum hydride.
The mechanism proceeds in three steps. First, the nucleophilic hydride ion attacks the carbonyl carbon of the acid halide to form a tetrahedral intermediate. Next, the carbonyl group is re-formed, and the halide ion departs as a leaving group, generating an aldehyde. A second nucleophilic attack by the hydride yields an alkoxide ion, which, upon protonation, gives a primary alcohol as...

Wolff–Kishner reduction involves converting aldehydes and ketones to alkanes using hydrazine and a base. The reaction converts a carbonyl group to a methylene group. The method was independently discovered by N. Kishner in 1911 and L. Wolff in 1912. The reduction is carried out in high-boiling solvents such as ethylene glycol and diethylene glycol because heat is required to deprotonate the N–H proton in one of the reaction steps.                                       ...

Wilhelm Rudolph Fittig discovered the pinacol coupling reaction in 1859. It is a radical dimerization reaction and involves the reductive coupling of aldehydes or ketones in the presence of hydrocarbon solvent to yield vicinal diols.

Carboxylic acids, upon reaction with strong reducing agents such as lithium aluminum hydride followed by hydrolysis, undergo reduction to form primary alcohols.