We went on to test a number of natural products and pharmaceuticals as nucleophiles in the reaction with 1a-TBS. These compounds all contained carboxylic acid moieties in their structures (Scheme 2c). A BOC-protected glycine derivative gave 8m in 55% yield. With biotin as the nucleophile, compound 8n was obtained in 44% yield. Acetyl salicylic acid gave 8o in quantitative yield (98% isolated yield), and ibuprofen gave 8p in 87% yield. With the aliphatic oleic acid, 8q was formed in 70% yield.