1559Tch17304-32211/3/0510:48Page313 风 Solutions to Problems313 :0D (b)HO 厂入 (e)See text sections 17-6 and 17-7 and Sudy Guide pp.306-307(b) (c) See text sections 17-6 and 17-7 and Study Guide pp. 306–307. 36. A double imine formation. Such a process may be carried out without catalysis, but mild acid is usually helpful. The mechanism for the first condensation is shown in detail, the second in abbreviated form. 37. H

RHN OH O RNH2
RH2N O H H
H2O N R
H N R
H RHN OH H CH3 H2O N N CH3
OH2 H CH3 H
N N CH3 product

NH2 H C C O CH3 CH3 N C (As above) H C C
O NH2 CH3 CH3 N C NH2 NH2 N H H OH C C O
NH2 CH3 CH3 H O
C C O CH3 CH3 H
OH2 C C O NH2 CH3 CH3 H2O N C HO O O

HO O HO OH HO O H
OH
O H OH O H
O O Solutions to Problems • 313 1559T_ch17_304-322 11/3/05 10:48 Page 313