Question

An epoxy ring can be prepared by

• A. DCC oxidation of alcohol
• B. Prevost reaction
• C. Darzens glycidic ester synthesis
• D. Swern oxidation

Answer 1

The Correct Option is C

The question asks for a method to prepare an epoxy ring. Let's evaluate the options given:

1. DCC Oxidation of Alcohol: DCC (Dicyclohexylcarbodiimide) is commonly used for forming amides and not for oxidation. It is not relevant to forming epoxy rings.
2. Prevost Reaction: This reaction involves the transformation of alkenes to glycols (vicinal diols) and some related modifications, but it does not directly lead to the formation of epoxy rings.
3. Darzens Glycidic Ester Synthesis: This is a well-known method for synthetizing epoxy rings. In this reaction, an α-halo ketone reacts with a base to form an α,β-epoxy ester. This is the correct method for preparing an epoxy ring.
4. Swern Oxidation: This method is used for converting primary and secondary alcohols to aldehydes and ketones, respectively. It does not facilitate epoxy ring formation.

Based on the explanations above, the correct answer is Darzens glycidic ester synthesis, as it directly involves the preparation of epoxides.

The general form of this reaction involves the nucleophilic attack of an α-halo ketone by a base, followed by cyclization to form the epoxy ring. This method is not only fundamental for synthesizing epoxy rings but also for various synthetic applications in organic chemistry.