When each of the compounds shown in Fig. P28.43 is heated in the presence of maleic anhydride, an intermediate is trapped as a Diels–Alder adduct. What is the intermediate formed in each reaction, and how is it formed from the starting material?

Transcribed Image Text:

(a) (b) (c) H₂C. maleic anhydride heat Son CH3 Figure P28.43 maleic anhydride heat maleic anhydride. 250 °C H H H₂C CH3 H H (mixture of stereoisomers)