Acid-catalysed monoacetalation of two 3-deoxyhexitols

Acid-catalysed monobutylidenation of $\text{3-}\text{deoxy}\text{-}\text{d}\text{-ribo-}\text{hexitol}$ yields the 2,4-acetal as the sole, detected product. $\text{3-}\text{Deoxy}\text{-}\text{l}\text{-xylo-}\text{hexitol}$ yields the 4,5-acetals as kinetic products, and the 4,6-acetal as the thermodynamic product.