Question

draw the major product formed in the following reaction

draw the major product formed in the following reaction

Answer 1

Concepts and reason

The three-membered cyclic ring contains 2 carbon atoms and 1 oxygen atom that are represented as epoxide. Epoxides are also known as cyclic ethers. The opening of Epoxide follows ${{\rm{S}}_{\rm{N}}}{\rm{2}}$ attack. Epoxide ring opening depends according to the type of nucleophile present.

Fundamentals

In the presence of weak nucleophile, the nucleophile attacks epoxide on more substituted site and follow ${{\rm{S}}_{\rm{N}}}{\rm{2}}$ type reaction. Example for weak nucleophile is ${{\rm{H}}_{\rm{2}}}{\rm{O,}}\,{\rm{C}}{{\rm{H}}_{\rm{3}}}{\rm{OH}}$ .

Example:

In the presence of strong nucleophile, the nucleophile attacks epoxide on less substituted site and follows ${{\rm{S}}_{\rm{N}}}{\rm{2}}$ type reaction. Example for weak nucleophile is ${\rm{KOH,}}\,{\rm{NaCN,}}\,\,{\rm{RMgX}}$

Example:

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