Question

The given products (either or both) are not possible from which of the following conformer(s) of above tetra alkyl ammonium hydroxide?

• A. The least stable conformer about $C_2-C_3$ bond.
• B. The most stable conformer about $C_2-C_3$ bond.
• C. The staggered conformation about $C_1-C_2$ bond.
• D. The conformer about C₂ - C₃ in which two methyl groups are in anti position.

Answer 1

Answer: (A), (B)

The correct options are
A The least stable conformer about $C_2-C_3$ bond.
B The most stable conformer about $C_2-C_3$ bond.

Dihedral angle between $NM{e}_3^{+}$ and H should be ${180}^o$ for elimination to occur. Or, the conformer should facilitate E2 via anti-periplanar configuration: