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14. Belaud, C.; Roussakis, C.; Letourneux, Y.; El Alami, N.;
afford ketone 4a. IR mmax neat/cmꢀ1 3300, 1650, 1445: H
NMR (300 MHz, CDCl3): 7.74 (2H, d, J = 7.5 Hz), 7.54
(1H, t, J = 7.35 Hz), 7.45 (2H, t, J = 7.5 Hz), 6.15 (1H, s),
5.81 (1H, s), 4.50 (2H, s), 2.77 (1H, m,); 13C NMR
(75 MHz, CDCl3): 197.9 (C@O), 146.23 (CH2@),
137.2 (@C), 132.4 (CHaromatic), 129.3 (CHaromatic), 128.2
(CHaromatic), 127.3 (Caromatic), 63.0 (CH2); Mass (EI,
70 eV) m/z (%): 51 (35), 77 (89), 105 (100), 116 (13), 144
(9), 161 (96).
´
Villieras, J. Synth. Commun. 1985, 15, 1233.
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Organocuprate addition to allylic acetate 5a: Typical
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procedure: A solution of propylmagnesium chloride
nPrMgCl (2 equiv) was added dropwise over a period of
15 min to a mixture of a-acetoxymethyl phenyl vinyl
ketone 5a (2 mmol) and a 1 M solution of LiCuBr2
(0.15 mL) diluted in dry THF (10 mL) at ꢀ78 ꢁC under
nitrogen. After a few minutes (TLC), the reaction mixture
was quenched with saturated NH4Cl solution (10 mL) then
extracted with ether (3 · 15 mL). The combined organic
layers were dried over MgSO4, filtered and evaporated
under reduced pressure. The crude product was purified by
column chromatography on silica gel (EtOAc/hexane, 2:8)
to afford 2-methylene-1-phenylhexan-1-one 6c. IR mmax
23. Hwu, J. R.; Hakimelahi, G. H.; Chou, C. T. Tetrahedron
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27. Synthesis of a-methylene-b-hydroxypropanone 4a: To a
magnetically stirred mixture of 2,4-diketoester 3a
(16 mmol) and 30% aqueous formaldehyde (3.5 mL) was
added at room temperature a gelatinous solution of
potassium carbonate (6–10 M, 33 mmol). The heteroge-
neous reaction mixture was stirred for 3 h then treated
with water. The solution was extracted with ether
(3 · 25 mL). The combined organic layers were dried over
anhydrous MgSO4, filtered and evaporated under reduced
pressure. The crude product was purified by column
chromatography on silica gel (EtOAc/hexane, 3:7) to
1
neat/cmꢀ1 1630, 1670, H NMR (300 MHz, CDCl3): 7.78
(2H, d, J = 7.50 Hz), 7.59 (1H, t, J = 7.35 Hz), 7.45 (2H, t,
J = 7.50 Hz), 5.81 (1H, s), 5.56 (1H, s), 2.47 (2H, t,
J = 6.9 Hz), 1.42 (4H, m), 0.92 (3H, t, J = 7.35 Hz);
13C NMR (75 MHz, CDCl3): 198.5 (C@O), 148.5
(CH2@), 137.9 (@C), 132.1 (CHaromatic), 129.5 (CHaromatic),
128.1 (CHaromatic), 125.0 (Caromatic), 32.0 (CH2), 30.3
(CH2), 22.4 (CH2), 13.9 (CH3). Mass (EI, 70 eV) m/z (%):
51 (19), 77(67), 105 (100), 145 (24), 159 (22), 188 (14).
28. Chamakh, A.; M’hirisi, M.; Amri, H. Synth. Commun.
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29. Mikolajczyk, M.; Grzejszczac, S.; Midura, W.; Zatorski,
A. Phosphorus Sulfur 1983, 18, 175–178.
´
30. Chamakh, A.; M’hirsi, M.; Villieras, J.; Lebreton, J.;
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