580 ESTER EN。 LATES The necessary alkyl halide in this synthesis is l-bromo-2-methylbutane CH, CH,CHCH,Br +CH,(COOCH, CH,)2-od+ CH, CH, CHCH, CH(COOCH, CH, ) I-Bromo-2-methylbutane Diethyl malonate Diethyl 2-(2-methylbutyl)malonate 1. HO. H-O 3. heat CH, CH,CHCH,CH,COH 4-Methy hexanoic acid (d) Once again disconnection reveals the necessary halide, which is treated with diethyl malonate CsH.CH,&CH,COH CsHCH,X CH,COH Alkylation of diethyl malonate with benzyl bromide is the first step in the preparation of 3-phenylpropanoic acid CGHSCHBr CH2(COOCH2CH3)ethanol C&HS CH CH(COOCH2 CH3)2 H+ CsH,CH, CH, COH Diethyl malonate Diethyl 2-benzylmalonate 3-Phenylpropanoic acid 21.8 Retrosynthetic analysis of the formation of 3-methyl-2-butanone is carried out in the same way as for other ketones CH CCH&CH CH, CCH 2CH,X H3 Derived from The two alkylation steps are carried out sequentially CHaCCH,COCH_CH3-ch.BT CH,CCHCOCH、NocH2 CHICCCOCH2CH3 3 hea CH,CCH(CH3) CH HC Eth Ethyl 2- methyl-3-oxobutanoate 2, 2-dimethyl-3-oxobutanoate Back Forward Main Menu TOC Study Guide Toc Student OLC MHHE WebsiteThe necessary alkyl halide in this synthesis is 1-bromo-2-methylbutane. (d) Once again disconnection reveals the necessary halide, which is treated with diethyl malonate. Alkylation of diethyl malonate with benzyl bromide is the first step in the preparation of 3-phenylpropanoic acid. 21.8 Retrosynthetic analysis of the formation of 3-methyl-2-butanone is carried out in the same way as for other ketones. The two alkylation steps are carried out sequentially. CH3CCHCOCH2CH3 NaOCH2CH3 CH3Br O O CH3 CH3CCH2COCH2CH3 NaOCH2CH3 CH3Br O O Ethyl acetoacetate Ethyl 2-methyl-3-oxobutanoate 1. HO, H2O 2. H CH3CCCOCH2CH3 O O H3C CH3 Ethyl 2,2-dimethyl-3-oxobutanoate CH3CCH(CH3)2 O 3-Methyl-2-butanone 3. heat CH3CCH 2CH3X O O CH3CCH CH3 CH3 3-Methyl-2-butanone (two disconnections as shown) Derived from ethyl acetoacetate Benzyl bromide C6H5CH2Br Diethyl malonate CH2(COOCH2CH3)2 NaOCH2CH3 ethanol Diethyl 2-benzylmalonate C6H5CH2CH(COOCH2CH3)2 1. HO, H2O 3-Phenylpropanoic acid C6H5CH2CH2COH O 2. H 3. heat Derived from diethyl malonate CH2COH O Required halide C6H5CH2 C6H5CH2X O CH2COH Diethyl malonate CH2(COOCH2CH3)2 NaOCH2CH3 ethanol 1-Bromo-2-methylbutane CH3CH2CHCH2Br CH3 1. HO, H2O 2. H 3. heat Diethyl 2-(2-methylbutyl)malonate CH3CH2CHCH2CH(COOCH2CH3)2 CH3 4-Methylhexanoic acid CH3CH2CHCH2CH2COH CH3 O 580 ESTER ENOLATES Back Forward Main Menu TOC Study Guide TOC Student OLC MHHE Website