Methods for preparing and purifying 2-monoacylglyceride compounds are disclosed. In one method, an unsaturated triglyceride is reacted with water, a C1-C8 alcohol, or a mixture thereof in the presence of a lipase to produce a mixture comprising a 1,3-dihydroxy-2-monoacylglyceride and fatty esters or acids. Reaction of the 1,3-dihydroxy-2-monoacylglyceride with an aldehyde or ketone gives a mixture comprising a 2-monoacylglyceride acetal or ketal. Fatty esters or acids are removed from the mixture as an overhead product by distillation or wiped-film evaporation to isolate a purified 2-monoacylglyceride acetal or ketal. The inventive methods provide a 2-monoacylglyceride protected at the 1- and 3-positions such that the acyl unit remains at the 2-position. The products are enriched in unsaturated fatty acid content when compared with the unsaturated fatty acid content of the original unsaturated triglyceride. Each method utilizes a practical purification scheme that avoids the scale-up or toxicity issues of commonly employed purification strategies.