How does nucleophilic attack open the ring of oxirane?

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heterocyclic compound There are many different sulfur-containing heterocycles. One of the best known is thiophene, C₄H₄S, derivatives of which occur as plant pigments and as other natural products such as biotin.

The three-membered ring of oxirane is highly reactive due to the significant ring strain inherent in its structure, making it much more susceptible to chemical reactions than typical open-chain ethers.1

The most characteristic reaction of oxirane is its susceptibility to attack by nucleophilic reagents, which causes the ring to open. During this process, a nucleophile attacks the ring, leading to the breaking of a carbon-oxygen bond. This reaction can proceed further, where additional molecules of the three-membered ring react with the initial product, eventually forming long, chainlike molecules known as polymers.1

Additionally, the oxirane ring can be opened through hydrolysis. In this reaction, the ring-opening is accompanied by the addition of the elements of water (H and OH), resulting in the formation of ethylene glycol.1