Question

Draw a structural formula for the product formed when alanine is treated with the following reagents. (a) CC(C)(C)C(=O)c1ccccc1 (b) O=C1c2ccccc2C(=O)C1(O)O (c) O=C(O)Cc1ccccc1 (d) CC(=O)OC(C)=O (e) Product from (c), L-Alanine ethyl ester, DCC (f) Product from (d), L-Alanine ethyl ester, DCC

Short answer

Question: Draw the structural formula for the product formed when alanine is treated with each of the following reagents. Answer: (a) For tert-butylbenzoate, the product is: N^H_3CH(CH_3)_2CC(O)_2c1ccccc1 (b) For 1,3-benzodioxole-4-carboxylic anhydride, the product is: N^H_3CHCOOC1c2ccccc2C(=O)C1(O)O (c) For benzoic acid, the product is: N^H_3CHCONHc1ccccc1 (d) For acetic anhydride, the product is: N^H_3CHCOOC(CH3)=O (e) For the reaction with L-Alanine ethyl ester and DCC after reacting with benzoic acid, the product is: N^H_3CHCONH-CH(COOCH_2CH_3)^$NHCc1ccccc1 (f) For the reaction with L-Alanine ethyl ester and DCC after reacting with acetic anhydride, the product is: N^H_3CHCONH-CH(COOCH_2CH_3)O=CCH_3

Step-by-step solution

(a) Product with CC(C)(C)C(=O)c1ccccc1

For this reaction, the reagent is tert-butylbenzoate (CC(C)(C)C(=O)c1ccccc1). The carboxyl group in alanine will react with this compound, which is an esterification reaction. The product will be alanine bonded with this ester group. The specific product will be: N^H_3CH(CH_3)_2CC(O)_2c1ccccc1

(b) Product with O=C1c2ccccc2C(=O)C1(O)O

For this reaction, the reagent is 1,3-benzodioxole-4-carboxylic anhydride (O=C1c2ccccc2C(=O)C1(O)O). This is a carboxylic anhydride, so once again, the carboxyl group in alanine will react with this reagent, forming an ester. The product will be alanine bonded with an ester group: N^H_3CHCOOC1c2ccccc2C(=O)C1(O)O

(c) Product with O=C(O)Cc1ccccc1

For this reaction, the reagent is benzoic acid (O=C(O)Cc1ccccc1). This is another carboxylic acid, and the reaction with alanine will be an amide formation. The product of this reaction will be alanine bonded with an amide group: N^H_3CHCONHc1ccccc1

(d) Product with CC(=O)OC(C)=O

For this reaction, the reagent is acetic anhydride (CC(=O)OC(C)=O). This is also a carboxylic anhydride. The carboxyl group of alanine will react with this reagent, forming an ester. The product will be alanine bonded with an acetyl group: N^H_3CHCOOC(CH3)=O

(e) Product from (c), L-Alanine ethyl ester, DCC

For this reaction, take the product from (c) along with a L-Alanine ethyl ester and react it with DCC (N,N'-dicyclohexylcarbodiimide), which is a dehydration agent. Its role is to create an amide bond between the two amino acids. Therefore, the product of this reaction will be a dipeptide with the sequence Alanine-Benzoyl Alanine Ethyl Ester: N^H_3CHCONH-CH(COOCH_2CH_3)^$NHCc1ccccc1

(f) Product from (d), L-Alanine ethyl ester, DCC

For this part, take the product from (d) along with a L-Alanine ethyl ester and react it with DCC (N,N'-dicyclohexylcarbodiimide), a dehydration agent. Its role is to create an amide bond between the two amino acids. Therefore, the product of this reaction will be a dipeptide with the sequence Alanine-Acetyl Alanine Ethyl Ester: N^H_3CHCONH-CH(COOCH_2CH_3)O=CCH_3