Question 1

&#8203;If lobes of like sign are on opposite sides of a molecule,and both orbitals must rotate in the same direction (either both clockwise or both counterclockwise),the kind of motion observed is:&#10;A)&#8203;suprafacial.&#10;B)&#8203;antarafacial.&#10;C)&#8203;disrotatory.&#10;D)&#8203;conrotatory.

Accepted Answer

When lobes of like sign are on opposite sides of a molecule and both orbitals rotate in the same direction, this is referred to as conrotatory motion. Disrotatory motion would occur if the two orbitals rotate in opposite directions. Supra- and antarafacial refer to the relative positions of the orbitals in a cyclic reaction, which is not necessarily applicable in this scenario.

Question 2

&#8203;According to the frontier orbital theory,the symmetry of electrocyclic reactions is determined by:&#10;A)&#8203;the total number of double bonds present in the molecule.&#10;B)&#8203;the symmetry of the HOMO.&#10;C)&#8203;the symmetry of the LUMO.&#10;D)&#8203;proper orientation of the HOMO of one atom with the LUMO of the other atom.

Accepted Answer

The symmetry of the Highest Occupied Molecular Orbital (HOMO) is crucial in determining the allowed pathway for electrocyclic reactions according to the frontier orbital theory.

Deck 30: Par 1