Question 1

The structure shown is a trityl (triphenylmethyl, Trt) group. Which functional group is most commonly protected using the trityl group in organic synthesis?

Accepted Answer

Alcohols

Question 2

Why is the trityl group (Trt) considered acid-labile as a protecting group?

Accepted Answer

It forms a highly stabilized carbocation upon acid treatment due to resonance with three phenyl rings.

Question 3

Which of the following conditions is typically used to remove the trityl protecting group from an alcohol?

Accepted Answer

Dilute acid, such as 1% TFA in DCM

Question 4

What is the main advantage of using the trityl group as a protecting group for alcohols?

Accepted Answer

It can be selectively removed under mild acidic conditions without affecting other acid-stable protecting groups.

Question 5

Which of the following best describes the mechanism for trityl group removal from an alcohol?

Accepted Answer

Formation of a trityl carbocation stabilized by resonance, followed by nucleophilic attack by water.

Question 6

In a molecule containing both a trityl-protected alcohol and a tert-butyl ester, which protecting group would be removed first under dilute acid conditions?

Accepted Answer

Trityl group

Question 7

Which property of the trityl group makes it a semi-orthogonal protecting group compared to tert-butyl groups?

Accepted Answer

It is removed by dilute acid, while tert-butyl groups require concentrated acid for removal.

Question 8

Which of the following is a plausible reason for choosing the trityl group to protect an alcohol in a peptide synthesis?

Accepted Answer

The trityl group can be removed under mild acidic conditions, leaving other base-labile protecting groups intact.

Question 9

Which of the following statements about the trityl group is FALSE?

Accepted Answer

It is removed by strong base such as NaOH.

Question 10

A chemist needs to selectively deprotect an alcohol in the presence of a tert-butyl ester. Which protecting group should be used for the alcohol to achieve this selectivity?

Accepted Answer

Trityl (Trt) group

Protecting Groups in Organic Chemistry: Principles, Applications, and Orthogonality

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