(tert-Butyldimethylsilyloxy)acetaldehyde is used in tetrahydropyran subunit construction, yielding addition products in good amounts in various total syntheses of biologically active molecules. Used in tetrahydropyran subunit construction. Application： (tert-Butyldimethylsilyloxy)acetaldehyde is a versatile reagent commonly used in synthetic glycobiology. It can act both as an aldol donor and an aldol acceptor in the stereocontrolled production of erythrose. It is used as an important reagent in the total synthesis of (+)-ambruticin, (−)-laulimalide, (−)-salinosporamide A, and (+)-leucascandrolide A. Employed in the construction of the key tetrahydropyran subunit in a recent synthesis of the marine natural product (–)-dactylodide.