Page 181 - Advanced Organic Chemistry Part B - Reactions & Synthesis

Scheme 2.15. Acylation of Ester Enolates with Acyl Halides, Anhydrides, and Imidazolides 153
A. Acylation with acyl halides and mixed anhydrides SECTION 2.3
1 a O O Acylation of Carbon
Nucleophiles
H OMgCH(CO C H ) C H )
PhCOCOC H + C 2 5 2 2 5 2 PhCOCH(CO 2 2 5 2
2 5
2 b 68 – 75%
COCl + C H OMgCH(CO C H ) COCH(CO C H )
2 2 5 2
2 2 5 2
2 5
NO 2 NO 2 82 – 88%
3 c O
–
O Na + O CCH 3 O
CH C CHCO C H + PhCOCl PhC CH CO C H PhCCH CO C H
2 2 5
2
2 2 5
3
2 2 5
68 – 71%
O
–
4 d O Na + O
O CCH 3
CH C CHCO C H + ClC(CH ) CO C H C H O C(CH ) C CHCO C H
2 2 5
3
2 2 5
2 3
2 3
2 2 5
2
2 5
5 e O 61 – 66%
O
R NLi (CH ) CCCl
3 3
2
CH CO C H LiCH CO C H (CH ) CCCH CO C H
2
2 2 5
3 3
2
2 2 5
2 2 5
3
–78°C
70%
6 f O
1) LDA
CH CO CH 3 CH O CCH C(CH ) CH 3
2
2 12
3
2
3
2
2) ClCO(CH ) CH 3 83%
2 12
+
3) H
B. Acylation with imidazolides
7 g
O
1) 25°C
CH 2 CN N + Mg(O CCH CO C H ) CH CCH CO C H
O 2 2 2 2 5 2 O 2 2 2 2 5
2) H +
8 h CH O 66%
3
CH 3
–78°C H +
+ LiCH CO C(CH )
O 2 2 3 3 1 h
C O
2
3 3
2
O N CCH CO C(CH )
N O
83%
9 i O
O NCH 2 – + CH CN N 65°C H + CH CCH NO 2
3
2
2
3
16 h 80%
O
10 j
H 1) N NCN N H O
t-BuO CNCHCO H O t-BuO CNCHCCH CO C H
2
2
2
2
2 2 5
O
CH(CH ) O CH(CH ) 83%
3 2
2) Mg 3 2
O
OEt
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b. G. A. Reynolds and C. R. Hauser, Org. Synth., IV, 708 (1963).
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d. M. Guha and D. Nasipuri, Org. Synth., V, 384 (1973).
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