Atomic Efficient Synthesis of 1,2,4-Butanetriol: Catalysts, Conversion Routes and Reaction Mechanism

1,2,4-Butanetriol (1,2,4-BTO) is a multifunctional C4 polyol used in the manufacture of energetic nitrate esters as well as the building block for fine chemicals, pharmaceuticals, and polymeric materials. However, selective and economically viable production of 1,2,4-BTO remains challenging, because existing routes differ markedly in feedstock cost, reaction efficiency, product specification, and downstream separation requirements. This review critically discussed the conventional chemical, hydrogenolysis, biological, and chemoenzymatic routes with emphasis on reaction selectivity, process efficiency, product quality, and separation burden. Most recent advances in catalyst design and reaction mechanism were further discussed in detail providing insights into opportunities and challenges in process development and optimization.