Predict the product formed by the reaction of diethy 1 malonate with sodium ethoxide and ethyl nitrite in ethanol solution. Write a mechanism for the formation of this product.

Diethyl malonate: \(CH_2(CO_2Et)_2\) Sodium ethoxide: \(NaOCH_2CH_3\) Ethyl nitrite: \(C_2H_5ONO\)

In diethyl malonate, thealpha carbon (the carbon between the two carbonyl groups) is a nucleophilic center since it contains acidic protons that can be deprotonated by a strong base. Sodium ethoxide is a strong base that can act as a nucleophile. The oxygen of the ethoxide ion is the nucleophilic center. Ethyl nitrite has an electrophilic nitrite group, and the nitrogen has a positive charge, making it an electrophilic center.

1. Deprotonation of diethyl malonate: Sodium ethoxide acts as a base and deprotonates the alpha carbon of diethyl malonate, forming an enolate ion and sodium ion. \(CH_2(CO_2Et)_2 + NaOCH_2CH_3 -> NaCH(CO_2Et)_2^- + CH_3CH_2OH\) 2. Nucleophilic attack: The enolate ion acts as a nucleophile and attacks the electrophilic nitrogen center in ethyl nitrite, producing a new C-N bond. \(NaCH(CO_2Et)_2^- + C_2H_5ONO -> CH(CO_2Et)_2N(OC_2H_5) + NaO^-\) 3. Rearrangement: The O-N bond in the intermediate is cleaved, and the O^- is eliminated. A new C=O bond is formed, and the ester group becomes an aldehyde. \(CH(CO_2Et)_2N(OC_2H_5) -> CH(CO_2Et)_2N=C(CHO) + C_2H_5O^-\) 4. Hydrolysis: The intermediate is hydrolyzed in the ethanol solution, and the aldehyde is converted into a carboxylic acid. \( CH(CO_2Et)_2N=C(CHO) + H_2O -> CH(CO_2Et)_2N=C(COOH)\)

The product formed by the reaction of diethyl malonate with sodium ethoxide and ethyl nitrite in ethanol solution is an α-nitro carboxylic acid: \((CH(CO_2Et)_2N=C(COOH))\)