Final answer:
The example problem of (+)-DET epoxide formation involves the regioselective cleavage of an oxirane ring with sodium azide in 2-methoxyethanol, followed by several steps to obtain the desired azido-alcohol product.
Step-by-step explanation:
An example problem of (+)-DET epoxide formation involves the regioselective cleavage of a oxirane ring with sodium azide in 2-methoxyethanol, followed by benzoylation of the hydroxyl group and subsequent removal of the acetal group using acidic hydrolysis. The resulting diol is then mesylated and deprotected to form an oxetane ring. Finally, the oxetane ring is deprotected to yield the desired azido-alcohol product.