Answer to Question #283107 in Organic Chemistry for Reens

Question

explain the following statement a) for diels alder reaction a diene must be able to adopt a cis geometry b) low molecular weight ozonides cannot isolated easily c) alkenes are readily hydroxylated

Answer 1

a) The reaction always creates a new six-membered ring. When intramolecular, another ring may also be formed. The diene component must be able to assume a s-cis conformation.

b) They are rarely isolated during the course of the ozonolysis reaction sequence. Molozonides are unstable and rapidly convert to the trioxolane ring structure with a five-membered C–O–O–C–O ring.

c) An example of an alkene addition reaction is a process called hydrogenation.In a hydrogenation reaction, two hydrogen atoms are added across the double bond of an alkene, resulting in a saturated alkane.