1559r_eh18_323-34311/3/0511:12Page329 EQA one can take place unde &8m-8m 36.Yes.Enamines (neutral)are much less basic than enolates (anionic)and show much less tendency to cause E2 elimination reactions. 37.Use the catalyst!Then it's straightforward 号号牙子 风 -心9 (E and Z E andAn acid-base reaction between cyclohexanone enolate and 2-methylcyclohexanone can take place under these conditions, leading to either possible enolate of the latter. Reaction of the new enolates with CH3I leads to double alkylation products. Enamines reduce this problem. They are less reactive and more selective than enolate ions. 36. Yes. Enamines (neutral) are much less basic than enolates (anionic) and show much less tendency to cause E2 elimination reactions. 37. Use the catalyst! Then it’s straightforward: 38. The direction of nucleophilic attack is shown, and the new bond is marked in the product with an arrow. Both the initial hydroxycarbonyl compound and the enone that forms upon dehydration are shown. (a) (b) OH CHO CHO and (E and Z) O H O H   OH CHO CHO and (E and Z) O H O H   N H H H  N OH N H O H (Section 17-8)  O  N N N O N H H2O    H H O O O   H H H O H H CH3   CH3  O CH3 or Solutions to Problems • 329 1559T_ch18_323-343 11/3/05 11:12 Page 329