Dolbier HW Solutions 491

Dolbier HW Solutions 491 - 585 ESTER ENOLATES (b)...

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Unformatted text preview: 585 ESTER ENOLATES (b) Saponification and decarboxylation of this -keto ester gives dibenzyl ketone. O O O 1. HO , H2O C6H5CH2CCHCOCH2CH3 C6H5CH2CCH2C6H5 2. H 3. heat C6H5 Dibenzyl ketone Ethyl 3-oxo-2,4diphenylbutanoate (c) O This process illustrates the alkylation of a -keto ester with subsequent saponification and decarboxylation. OCH2CH O NaOCH2CH3 C6H5CH2CCHCOCH2CH3 H 2C CHCH2Br O CH2 1. HO , H2O C6H5CH2CCCOOCH2CH3 C6H5 C6H5 C6H5CH2CCHCH2CH 2. H 3. heat CH2 C6H5 1,3-Diphenyl-5-hexen-2-one Ethyl 3-oxo-2,4diphenylbutanoate (d ) The enolate ion of ethyl phenylacetate attacks the carbonyl carbon of ethyl benzoate. O O OCH2CH3 C6H5C O C6H5CCHCOCH2CH3 C6H5CHCOCH2CH3 C6H5 O (e) Ethyl 2,3-diphenyl3-oxopropanoate Saponification and decarboxylation yield benzyl phenyl ketone. O O O C6H5CCHCOCH2CH3 C6H5 1. HO , H2O 2. H 3. heat Ethyl 3-Oxo-2,3-diphenylpropanoate ( f) O C6H5CCH2C6H5 Benzyl phenyl ketone This sequence is analogous to that of part (c). OCH2CH O C6H5CCHCOCH2CH3 NaOCH2CH3 H 2C CHCH2Br CH2 C6H5CCCOOCH2CH3 C6H5 C6H5 O 1. HO , H2O C6H5CCHCH2CH 2. H 3. heat CH2 C6H5 1,2-Diphenyl-4-penten-1-one 21.17 (a) The Dieckmann reaction is the intramolecular version of the Claisen condensation. It employs a diester as starting material. O O O CH3CH2OC(CH2)5COCH2CH3 Diethyl heptanedioate Back Forward Main Menu TOC Study Guide TOC O COCH2CH3 1. NaOCH2CH3 2. H Ethyl (2-oxocyclohexane)carboxylate Student OLC MHHE Website ...
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This note was uploaded on 09/30/2011 for the course CHM 2210 taught by Professor Reynolds during the Fall '01 term at University of Florida.

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