Final Answer:
Under basic conditions, nucleophiles will attack the epoxide at the least substituted position.
Step-by-step explanation:
In organic chemistry, the reactivity of epoxides toward nucleophiles is influenced by the degree of substitution at the carbon atoms involved. The term "substituted" refers to the number of alkyl or aryl groups attached to the carbon atoms adjacent to the epoxide ring. When nucleophilic attack occurs under basic conditions, the nucleophile typically targets the carbon with fewer substituents, known as the least substituted position.
The rationale behind this lies in the steric hindrance and electronic effects associated with the epoxide ring. The least substituted carbon is less hindered by bulky groups, allowing the nucleophile to approach and attack more easily.
Moreover, the carbon in the least substituted position is more electron-deficient due to its lower degree of substitution, making it more susceptible to nucleophilic attack. This preference for the least substituted position is a fundamental concept in understanding the regioselectivity of nucleophilic ring-opening reactions of epoxides under basic conditions.
In summary, under basic conditions, nucleophiles selectively attack the least substituted carbon in an epoxide ring due to a combination of steric and electronic factors. This regioselectivity is crucial in predicting and understanding the outcome of reactions involving epoxides and nucleophiles.