Question

5. The same class of chemicals that cause stink-bugs to stink (an Exam 4 question) is responsible for some of the major flavors and aromas of cilantro and roasted peanuts really!). A food chemist was interested in making derivatives of Odor A, hopingbie find one that has some desirable flavor characteristics without such an undesirad smell. She mixed Odor A with a small protein diagramed below (named N-+-Pr-l L-Ala-NH2) along with NaBH,CN. NH2 N--Pr-L-Ala-L-Ala-NH2 NH NaBH CN Odor A (8 pts) In the space above, draw the most likely product(s). a. (2 pts) What is the bond order of the bond between the carbonyl carbon and the alpha carbon in Odor A? Circle the one best choice: [less than 1 1.1-1.4] [1.5] [1.6-1.9] 12] [greater than 2] [there is no such bond in this compound b. c. (2 pts) Would the Gabriel Synthesis (phthalimide, hydroxide, etc.) be a good way to synthesize any part of N- -Pr-L-Ala-L-Ala-NH2? Choose the one best answer among the following: i. Yes, because Gabriel does not involve LiAIH ii. No, because it has no amines ii. No, because the amine has no adjacent CH2 group iv. No, for reasons related to steric hindrance v. No, for reasons related to whether the amine is primary vi. No, for reasons related to stereochemistry

Answer 1

A) The image shown below is the clear concept of reductive ammination using the reducing agent NaBH3CN -

Odor A Nil 2- 0 NaB3CN P1

B) The bond order between the carbonyl carbon and the alpha carbon of Odor A must be 1.5 due to the conjugation between the both the carbon atoms as the electron density from the alkene of the alpha carbon are being transferred to the anti bonding orbital of the carbon of the carbonyl group as both the orbitals are parallel to each other.

Thus the carbonyl and the alpha carbon bonds will have single as well as double bod character.

The image shown will make an good explanation to this -

Thus the bond has both sungle bond and double bond pharacter

C) Yes, Gabriel Pthalamide will be the good way to synthesize any part of the given amine acid because Its synthesis does not involve the powerful reducing agent LiAlH4 otherwise it will reduce the amide functional groups to amine.