An Enantioconvergent Synthesis of (R)‐4‐Aryloxy‐1‐butyne‐3‐ols for Prostanoid Side Chains

The single enantiomer title alcohols, useful as ω-side chain precursors for pharmaceutically important prostaglandin analogues were synthesised from the corresponding racemic alcohols by a convenient 4-step sequence. After enzymatic acylation of the alcohol with a vinyl carboxylate, the residual (S)-alcohol in the mixture was converted to the mesylate. Subsequent displacement with the corresponding carboxylate anion, followed by enzymatic deacylation gave the desired (R)-alcohol. In this way, all of the starting alcohol was utilised without the need for separation of the starting material and product after the bioresolution.