CPC CPC Organic Chemistry & Synthesis

Question 1

Which reaction mechanism involves the simultaneous breaking and forming of bonds in a single concerted step?

Accepted Answer

SN2

Answer

SN2 (bimolecular nucleophilic substitution) proceeds via a concerted mechanism with simultaneous bond breaking and formation in one transition state.

Question 2

In a Diels-Alder reaction, the diene must be in which conformation for the reaction to proceed?

Accepted Answer

s-cis

Answer

The diene must adopt the s-cis conformation so that both double bonds can overlap simultaneously with the dienophile's π system.

Question 3

Which reagent is most commonly used to reduce an aldehyde to a primary alcohol?

Accepted Answer

NaBH4 or LiAlH4

Answer

Both NaBH4 and LiAlH4 can reduce aldehydes to primary alcohols, with NaBH4 being milder and LiAlH4 being more powerful.

Question 4

What is the product of ozonolysis of a terminal alkene followed by reductive workup (Me2S)?

Accepted Answer

Aldehyde and formaldehyde

Answer

Reductive workup of a terminal alkene ozonolysis yields an aldehyde from the internal carbon and formaldehyde from the terminal CH2.

Question 5

Which of the following best describes a Grignard reagent acting as a nucleophile?

Accepted Answer

Carbon-metal bond donating electrons to an electrophile

Answer

Grignard reagents (RMgX) act as nucleophiles because the polarized C–Mg bond makes the carbon electron-rich, allowing it to donate electrons to electrophiles.

(CPC) Certified Professional Chemist Practice Test

(CPC) Certified Professional Chemist Practice Test

CPC CPC Organic Chemistry & Synthesis