ORGANOMETALLIC COMPOUNDS 349 (a) 1-Pentanol is a primary alcohol having one more carbon atom than 1-bromobutane. Retrosyn- thetic analysis suggests the reaction of a Grignard reagent with formaldehyde CH,CHCH,CH,+CH,OH CH CH, CH,CH Mgx HC=( 1-Pentanol Butylmagnesium halid Formaldehyde An appropriate synthetic scheme is CH3 CH,CH,CH, Br CHa CH,CH,CH,MgBr CH3 CH, CH,CH,CH,OH 1-Pentanol (b) 2-Hexanol is a secondary alcohol having two more carbon atoms than l-bromobutane vealed by retrosynthetic analysis, it may be prepared by reaction of ethanal(acetaldeh ith butylmagnesium bromide CHCHCH,,+CHCH,> CHCH,,Mgx + CHCH OH 2-Hexanol Buty magnesium halide acetaldehyde The correct reaction sequence is I CH,CH CHaCH,CH, BI CHa,CH, CH, MgBr H CHCH..CHCH diethyl ether Butylmagnesium bromide 2-Hexanol (c) 1-Phenyl-l-pentanol is a secondary alcohol Disconnection suggests that it can be prepared from butylmagnesium bromide and an aldehyde; benzaldehyde is the appropriate aldehyde CH,CH, CH, CH,+CH CHaCH,CHCH,Mgx+ I-Phenyl-l-pentanol Butylmagnesium halide Benzaldehyde CHa,CHLCH, Mg Br Fo CHCHCHCHCH Butylmagnesium bromide (d) The target molecule 3-methyl-3-heptanol has the structure CH CH CHCHCH CH, CH3 Back Forward Main Menu TOC Study Guide Toc Student OLC MHHE Website(a) 1-Pentanol is a primary alcohol having one more carbon atom than 1-bromobutane. Retrosyn￾thetic analysis suggests the reaction of a Grignard reagent with formaldehyde. An appropriate synthetic scheme is (b) 2-Hexanol is a secondary alcohol having two more carbon atoms than 1-bromobutane. As re￾vealed by retrosynthetic analysis, it may be prepared by reaction of ethanal (acetaldehyde) with butylmagnesium bromide. The correct reaction sequence is (c) 1-Phenyl-1-pentanol is a secondary alcohol. Disconnection suggests that it can be prepared from butylmagnesium bromide and an aldehyde; benzaldehyde is the appropriate aldehyde. (d) The target molecule 3-methyl-3-heptanol has the structure C OH CH3 CH3CH2CH2CH2 CH2CH3 1. ether 2. H3O Benzaldehyde CH O 1-Phenyl-1-pentanol CHCH2CH2CH2CH3 OH CH3CH2CH2CH2MgBr Butylmagnesium bromide Butylmagnesium halide CH3CH2CH2CH2MgX 1-Phenyl-1-pentanol CH3CH2CH2CH2 CH OH Benzaldehyde CH O CH3CH2CH2CH2Br 1-Bromobutane Butylmagnesium bromide CH3CH2CH2CH2MgBr 2-Hexanol CH3CH2CH2CH2CHCH3 OH Mg diethyl ether 2. H3O 1. CH3CH O 2-Hexanol Butylmagnesium halide Ethanal (acetaldehyde) CH3CH2CH2CH2MgX CH3CH O CH3CH2CH2CH2 CHCH3 OH CH3CH2CH2CH2Br 1-Bromobutane Mg diethyl ether Butylmagnesium bromide CH3CH2CH2CH2MgBr CH3CH2CH2CH2CH2OH 1-Pentanol 2. H3O 1. HCH O CH3CH2CH2CH2 1-Pentanol Butylmagnesium halide Formaldehyde CH2OH O CH3CH2CH2CH2MgX H2C ORGANOMETALLIC COMPOUNDS 349 Back Forward Main Menu TOC Study Guide TOC Student OLC MHHE Website