A general procedure for the synthesis of 1-O-acyl-β-D-glucuronic acids using the benzyl 1-O-trichloroacetimidoyl-2,3,4-tri-O-benzyl-D- glucopyranuronate 6 as donor is exemplified by the synthesis of the urine metabolites of (S)-naproxen, desmethyl (S)-naproxen, indoprofen, and carboxymefloquine. The key intermediate benzyl 2,3,4-tri-O-benzyl-D- glucopyranuronate 5 is easily accessible in four steps (29%) from the peracetylated β-D-glucuronic acid 1.