Which of the Following Statements About Thermal Electrocyclic Reactions Is

Multiple Choice

Which of the following statements about thermal electrocyclic reactions is not true?

A) The number of s bonds in the conjugated polyene determines whether rotation is conrotatory or disrotatory.
B) Thermal electrocyclic reactions occur in a disrotatory fashion for a conjugated polyene with an odd number of p bonds.
C) Thermal electrocyclic reactions occur in a conrotatory fashion for a conjugated polyene with an even number of p bonds.
D) In thermal reactions,we consider the orbitals of the HOMO of the ground state electronic configuration to determine the course of the reaction.