The protection of aldehydes and ketones by the formation of acetals is important in the preparation of a variety of multi- functional organic molecules.2 Numerous publications have described the formation of acetals under acidic conditions,3 the main disadvantages of these methods being the use of uncommon reagents and difficult work-up. Clay minerals are known to catalyse a variety of organic reactions in which the clay catalyst acts as a solid Lewis acid or Brønsted ...
