Organic Chemistry Mechanism Challenge 2

The video tutorial explains a chemical synthesis mechanism, focusing on electron pushing arrows. It covers the use of NaCN in DMSO as a nucleophile, attacking an alkyne conjugated with a carbonyl. The process involves forming an enolate on an allene, closing a six-membered ring, and a tautomerization from keto to enol form to achieve an aromatic tricyclic structure.

What is the primary goal when analyzing the synthesis problem presented in the video?

• To memorize the starting materials

• To understand the mechanism with electron-pushing arrows

• To calculate the yield of the reaction

• To identify the solvent used

What role does CN- play in the reaction mechanism?

• It is a catalyst

• It is an electrophile

• It acts as a solvent

• It is a nucleophile

Why is the attack of CN- on the alkyne considered unusual?

• Because alkynes are not conjugated with carbonyls

• Because CN- is not a strong nucleophile

• Because nucleophiles usually attack carbonyls

• Because alkynes are typically unreactive

What is formed when the allene enolate attacks and forms a new ring?

• A four-membered ring

• A five-membered ring

• A six-membered ring

• A seven-membered ring

What happens to the methoxy group during the formation of the new ring?

• It is kicked off

• It forms a new bond with CN-

• It is converted to a hydroxyl group

• It is retained in the structure

What is the final structural change that occurs during tautomerization?

• Formation of a new carbonyl group

• Loss of aromaticity

• Conversion of an alkene to an alkyne

• Formation of an aromatic tricyclic structure

Why is the enol tautomer favored in the final step?

• Because it forms a new carbonyl group

• Because it is aromatic

• Because it is more stable than the keto form

• Because it has a higher energy state