ORGANIC CHEMISTRY Chapter 17 17.4b Synthetic applications OH OH OH Nabh 2RCH’CHO RCHoCH-CHCHO RCHoCH-CHCHOH HO R R Aldehyde An aldol HA a13-diol HoO RCHOCH=CCHO H2/N R high LiAIH4 pressure An a B-unsaturated aldehyde H/Pd-C RCH,,oH RCH2 CH2-CHCHO RCH,CH=CCH,OH R R R A saturated alcohol An aldehyde An allylic alcohol Department of Chemistry, Xiamen University
ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 17 17.4B Synthetic Applications 2 RCH2CHO OH H2O RCH2CH CHCHO R OH NaBH4 RCH2CH CHCH2OH R OH Aldehyde An aldol HA A 1,3-diol H2O RCH2CH CCHO R LiAlH4 RCH2CH CCH2OH R H2/Ni high pressure RCH2CH2 CHCH2OH R H2/Pd-C RCH2CH2 CHCHO R A saturated alcohol An α,β-unsaturated aldehyde An aldehyde An allylic alcohol
ORGANIC CHEMISTRY Chapter 17 17. 4C The reversibility of Aldol Additions o The aldol addition is reversible- retro-aldol reaction OH OH CH3-C-CH2-C-CH3-CH3-C-CH2-C-CH HO CH CH (5%) H2O CH3 -C CH2-C-CH3 2 CH3-C-CH3 OH CH (95% Department of Chemistry, Xiamen University
ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 17 17.4C The Reversibility of Aldol Additions The aldol addition is reversible — retro-aldol reaction. CH3 C OH CH2 C CH3 O OH + CH3 CH3 C O CH2 C CH3 O CH3 H2O CH3 C O CH3 CH3 C CH3 O CH2 C CH3 O OH H2O (5%) 2 (95%)