ORGANIC CHEMISTRY Chapter 5 o If a reaction that leads to the formation of enantiomers produces a preponderance of one enantiomer over its mirror image, the reaction is said to be enantioselective o for a reaction to be enantioselective. a chiral reagent, solvent, or catalyst must assert an influence on the course of the reaction Department of Chemistry, Xiamen University
ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 5 If a reaction that leads to the formation of enantiomers produces a preponderance of one enantiomer over its mirror image, the reaction is said to be enantioselective. For a reaction to be enantioselective, a chiral reagent, solvent, or catalyst must assert an influence on the course of the reaction
ORGANIC CHEMISTRY Chapter 5 5.9B Enantioselective Synthesis O C.IIIlCH2Ca3 HO CH C. III1CH2CH CH H H--H (R)-2-Butanol 50% H--H H I CH CH3 0-C C. IllICHbCH CH CH 50% (S)-2-Butanol Department of Chemistry, Xiamen University
ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 5 5.9B Enantioselective Synthesis HO C CH2CH3 H CH3 (R)-2-Butanol O C CH2CH3 CH3 H H 50% H H O C CH2CH3 CH3 H C CH2CH3 HO CH3 (S)-2-Butanol 50%
ORGANIC CHEMISTRY Chapter 5 o()LiAIHCH OH CH CH OH H H (2)H2O H H Ph CH(CH3h Ph CH(CH3h pI CH(CH3)2 5.0 H O (1LiAIH4 CH3)3C OH (CH33C (2)H2O 91% H More stable OH (CH3)3C H Less stable H Department of Chemistry, Xiamen University
ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 5 C Ph CH3 H CH(CH3)2 O (1) LiAlH4 (2) H2O C Ph CH3 H CH(CH3)2 OH H C Ph CH3 H CH(CH3)2 H OH + 5.0 1 O (CH3)3C H (1) LiAlH4 (2) H2O OH (CH3)3C H H OH (CH3)3C H H 91% 9% + More stable Less stable
ORGANIC CHEMISTRY Chapter 5 g many enzymes have also found use in the organic chemistry laboratory where organic chemists take advantage of their properties to bring about enantioselective reactions lease OEt OEt H-OH Ethyl(+)-2-fluorohexanoate ee>99 lan ester that is a racemate of (R)and(s) forms OH H-OEt ee>69 Department of Chemistry, Xiamen University
ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 5 Many enzymes have also found use in the organic chemistry laboratory, where organic chemists take advantage of their properties to bring about enantioselective reactions. C F O OEt H OH lipase C F O OEt C F O OH %ee > 99 %ee > 69 + + H OEt Ethyl (±)-2-fluorohexanoate [an ester that is a racemate of (R) and (S) forms]
ORGANIC CHEMISTRY Chapter 5 5.10 Chiral Drugs Department of Chemistry, Xiamen University
ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 5 5.10 Chiral Drugs