Synthesis Topic 1

Question 1

What is tautomerism?

Answer 1

A reaction that involves the intramolecular transfer of a proton.

Question 2

How electron withdrawing substituents affect NMR?

Answer 2

They deshield the nuclei and shift their NMR signals downfield (higher chemical shift)

Question 3

How electron donating substituents affect NMR?

Answer 3

They shield the nuclei and shift their NMR signals upfield (lower chemical shift)

Question 4

What are the names of substituents around a ring?

Answer 4

Ipso, ortho, meta, para

Question 5

Why the bonding molecular orbitals are lower in energy than the individual, isolated p_z atomic orbitals?

Answer 5

It is because all electrons occupy these low energy orbitals, decreasing the overall energy in the system.

Question 6

What is Huckel’s Rule of Aromaticity?

Answer 6

Planar, fully conjugated, cyclic system with (4n+2) π electrons are exceptionally stable and are said to be aromatic.

Question 7

What are anti-aromatic compounds?

Answer 7

Planar, fully conjugated, cyclic systems with (4n) π electrons. They are very unstable.