1559r.ah21.373-38811/9/0516:17Page396 EQA 386.chapter 21 AMINES AND THEIR DERIVATIVES:FUNCTIONAL GROUPS CONTAINING NITROGEN 53.Work backward:make sure you include all 15 carbons in your answer. C6Hs、CO2CH2CH C6H5、CO,CHCH3 2 (a)HC CH 00 +2CH20 CHs、C0 2CH-CH3 C6H、CO-CH-CH3 CoH5、C0zCH,CH or CH N CH H-C CHa CH3 e correct structur (b)Big hint:CH COCH CH can be converted into pethidine.This strongly suggests that CHOCHO CH5、Co,CHCH CH、CO2CHCH H.CHNh CHO CHO CHO [CH、CO,CHCH CH、CO,CH,CH CH5、C0,CH,CH CHO NH The sequence is actually carried out all at once,by mixing amin dialdehyde,and NaBHCN together The dialdehyde synthesis: CH、CO-CH-CH CoH5CO,CHCH CHO CHO BrCH2 H H53. Work backward; make sure you include all 15 carbons in your answer. (a) (The extra CH3 on nitrogen is needed to give the correct molecular formula.) No way yet to choose which of the three is the correct structure. (b) Big hint: can be converted into pethidine. This strongly suggests that pethidine is the amine with the six-membered ring because that one is readily accessible from the dialdehyde as follows: The sequence is actually carried out all at once, by mixing amine, dialdehyde, and NaBH3CN together. The dialdehyde synthesis: C6H5CH2CO2CH2CH3 BrCH2 CH2Br  C C H H C6H5 CO2CH2CH3 C6H5 CO2CH2CH3 1. O3, CH2Cl2 2. Zn, H, H2O CHO CHO 2 LDA, THF (Double alkylation) C6H5 CO2CH2CH3 C6H5 CO2CH2CH3 CHO NaBH3CN CH3CH2OH CH3 N CH3 NH  C6H5 CO2CH2CH3 CH3 N C6H5 CO2CH2CH3 C6H5 CO2CH2CH3 H, CH3NH2 CHO CHO CHO NaBH3CN CH3CH2OH CH3 N C6H5 CO2CH2CH3 CHO CHO C6H5 CH3 CO2CH2CH3 C6H5 CO2CH2CH3 C6H5 CO2CH2CH3 CH3 H3C CH3 CH3 N CH3 N N or or C6H5 C6H5 CO2CH2CH3 CO2CH2CH3 Ozonolysis 2 Hofmann cycles C HC CH O O  2 CH2O 386 • Chapter 21 AMINES AND THEIR DERIVATIVES: FUNCTIONAL GROUPS CONTAINING NITROGEN 1559T_ch21_373-388 11/9/05 16:17 Page 386