Abstract: Disclosed is a novel capping-and-tagging (“cap-tag”) strategy that aids in the purification of compounds assembled by multi-step synthetic methods. The incorporation of a unique cap-tag into undesired intermediates during a multi-step synthesis allows for the straightforward removal of these undesired compounds at the conclusion of the synthetic protocol by several methods based on affinity chromatography and scavenging resins. Importantly, this invention may be exploited in any automated synthetic protocol. In preferred embodiments, the cap-tag system is exploited for the purification of carbohydrates prepared via automated solid-phase methods.