5) Considering both configurational and conformational factors, select the most stable form of 2,4 -hexadiene. I I III IV V 14) From the standpoint of reactivity, which is the poorest choice of dienophile to react with 2,3 -dimethyl-1,3butadiene in a Diels-Alder reaction? I II III IV V 15) Which reaction would produce the following compound? I II a) I b) II c) III d) IV e) None of these choices. 16) does not undergo the Diels-Alder reaction as a diene because: a) a bicyclic ring system cannot function as the diene component. b) it cannot adopt the s-cis conformation. c) it lacks electron-withdrawing groups. d) it lacks strong electron-releasing groups. e) the two double bonds are further apart than in a non-cyclic conjugated system