Orbital Overlap in Esters :0: lone pair donation from oxygen stabilizes the carbonyl group of an ester *stabilization greater than comparable stabilization of an anhydride or thioester
: : : 1 2 -
least stabilized C=O O RCCI 99 RCOCR' RCSR' RCOR most stabilized C=O
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Orbital Overlap in Amides R lone pair donation from nitrogen stabilizes the carbonyl group of an amide .N is less electronegative than O;therefore, amides are stabilized more than esters and anhydrides
: . 4$ : 1 2 -
Orbital Overlap in Amides R NR'2 一R0=R amide resonance imparts significant double-bond character to C.一V bond activation energy for rotation about C-N bond is 75-85 kJ/mol C-N bond distance is 135 pm in amides versus normal single-bond distance of 147 pm in amines
%3 . %3 1=6= >? %3 /0=. /31 1 2 -
least stabilized C=O RCCI 99 RCOCR' RCSR' RCOR' RCNR'2 most stabilized C=O
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