ESTER EN。 LATES 583 Basic ester hydrolysis followed by acidification and decarboxylation gives the diketone 3-(2 oxopropyl)cycloheptanone as the major product of the reaction sequence 1. KOH ethanok-water CHCOCHCH CHCCH 3. heat CH3 cycloheptanone (52%o) 21. 14 (b) The a-carbon atom of the ester bears a phenyl substituent and a methyl group. Only the methyl group can be attached to the a carbon by nucleophilic substitution. Therefore generate the enolate of methyl phenylacetate with lithium diisopropylamide (lda)in tetrahydrofuran THF) and then alkylate with methyl iodide CH__ CO, CH,- THE C6HSCH=C → CH CHCO2CH3 OCH Methyl phenylacetate Methyl (c) The desired product corresponds to an aldol addition product CHC6H5 HCCSH Therefore convert cyclohexanone to its enolate and then treat with benzaldehyde CHCH L LDA THF 3.H2O Cyclohexanone 1-(2-Oxocyclohexyl)I (d) This product corresponds to the addition of the enolate of tert-butyl acetate to cyclohexanone OH 0 +: CH, COC(CH3)3 CH,COC(CH3)3 Generate the enolate of tert-butyl acetate with lithium diisopropylamide; then add cyclohexa 1. LDA, THF OH CH3CO2C(CH3)3 2. cyclohexanone 3.H2O CH, CO,C(CH3) tert-Butyl acetate (1-hydroxycyclohexyl)acetate Back Forward Main Menu TOC Study Guide Toc Student OLC MHHE WebsiteBasic ester hydrolysis followed by acidification and decarboxylation gives the diketone 3-(2- oxopropyl)cycloheptanone as the major product of the reaction sequence. 21.14 (b) The -carbon atom of the ester bears a phenyl substituent and a methyl group. Only the methyl group can be attached to the carbon by nucleophilic substitution. Therefore generate the enolate of methyl phenylacetate with lithium diisopropylamide (LDA) in tetrahydrofuran (THF) and then alkylate with methyl iodide. (c) The desired product corresponds to an aldol addition product. Therefore convert cyclohexanone to its enolate and then treat with benzaldehyde. (d) This product corresponds to the addition of the enolate of tert-butyl acetate to cyclohexanone. Generate the enolate of tert-butyl acetate with lithium diisopropylamide; then add cyclohexa￾none. 1. LDA, THF 2. cyclohexanone 3. H3O CH2CO2C(CH3)3 OH tert-Butyl (1-hydroxycyclohexyl)acetate CH3CO2C(CH3)3 tert-Butyl acetate O O CH2COC(CH3)3 OH CH2COC(CH3)3 O 1. LDA, THF 2. C6H5CHO 3. H3O O Cyclohexanone O OH CHC6H5 1-(2-Oxocyclohexyl)-1- phenylmethanol O OH CHC6H5 O HCC6H5 O LDA THF CH3I C6H5CHCO2CH3 CH3 Methyl 2-phenylpropanoate C6H5CH OCH3 OLi C Enolate of methyl phenylacetate C6H5CH2CO2CH3 Methyl phenylacetate CHCOCH2CH3 O O 1. KOH, ethanol–water 2. H 3. heat CH2CCH3 O O 3-(2-Oxopropyl)- CH cycloheptanone (52%) O 3 C ESTER ENOLATES 583 Back Forward Main Menu TOC Study Guide TOC Student OLC MHHE Website