Aldehydes and ketones react with open- chain __ , __ _____ to produce ______ _______.

If the 1, 2 diol is attached to a ring as in a monosaccharide, formation of the cyclic acetals occurs only _________________________________________________________.

Cyclic acetals are commonly used to protect ________ ____ hydroxyl groups of a sugar while reactions are carried out on other parts of the molecule.

When acetals are formed from acetone they are called acetonides. What are acetonides?