Protecting groups are a vital tool in the synthesis of multifunctional molecules such as valuable third generation pharmaceuticals. When a reaction must be carried out at a specific reaction site, protecting groups are often used to temporarily block other sensitive reaction sites on the molecule. Substituted benzyl alcohols are particularly useful as protecting groups. They are prepared by reacting electrophiles with a simple derivative of benzyl alcohol, benzyl alcohol ester. Although this reaction proceeds in excellent yield, it results in a mixture of isomers with similar physical properties. Separation of the isomers is expensive and technically difficult. This project is focused on the continued investigation of a novel membrane-based process to address the above problem. The process couples a selective catalyzed reaction with membrane-based separation. Each reaction product is a commercially important protecting group in pharmaceutical synthesis.