First synthesis of α-(3-R-1-adamantyl)sulfoacetic acids and their derivatives

Article abstract of DOI:10.1016/j.tet.2012.04.006

By sulfonation of 3-R-1-adamantylacetic acids 1 with H₂SO ₄ in trifluoroacetic anhydride (TFAA), the previously unknown α-(3-R-adamantyl)sulfoacetic acids 2 were obtained. In the case of 1-adamantylacetic acid 1a, the use of ～1 equiv of H₂SO ₄ led to only 1-adamantylacetic acid 2a, while with an excess of the reactant the hydroxylation of the adamantane tertiary C-H bond also occurred. It is assumed that the bis(trifluoroacetyl)sulfate generated in situ from H ₂SO₄ and TFAA is responsible both for sulfonation and oxidation steps. The adamantylated sulfoacetic acids were used for the preparation of a series of derivatives by modifications of carboxylic, sulfonic acid, and tertiary adamantane OH-groups. Due to the use of TFAA as a medium, a series of derivatives of sulfoacetic acids was obtained directly from acids 1 within one-pot procedures. Some of the synthesized compounds possess anti-HSV activity.