Emmanuel Leroy et al.
FULL PAPERS
Experimental Section
7-[(3-Cyano-3-(octanoyloxy)prop-1-yl)oxy]-2H-1-
benzopyran-2-one (1d)
To a solution of cyanohydrin 2 (120 mg, 0.49 mmol) in dry
dichloromethane (4 mL) were added octanoyl chloride
(252 mL, 3 equivalents) and dry pyridine (120 mL) at 08C. The
reaction mixture was stirred overnight, extracted with EtOAc
(3 Â 10 mL), dried on Na2SO4 and evaporated. Flash chroma-
tography (hexane/EtOAc 6/4, Rf 0.40) gave ester 1d as a
colorless oil; yield: 92 mg (51%); IR (CHCl3): n 2933, 2860,
2401, 1732, 1615, 1216, 838 cmÀ1; 1H NMR (300 MHz, CDCl3):
d 7.65 (d, 1H, J 9.2 Hz), 7.40 (d, 1H, J 8.7 Hz), 6.85 (dd,
1H, J 8.8 Hz, J 2.2 Hz), 6.81 (d, 1H, J 2.2 Hz), 6.28 (d, 1H,
J 9.5 Hz), 5.62 (dd, 1H, J 6.6 Hz), 4.18 (m, 2H), 2.42 (m,
4H), 1.64 (m, 2H), 1.26 (m, 8H), 0.87 (t, 3H, J 6.6 Hz);
13C NMR (50 MHz, CDCl3): d 171.8, 161.1, 161.0, 155.7,
143.2, 128.9, 116.4, 113.6, 113.1, 112.8, 101.3, 62.9, 57.9, 33.6,
General
All reactions were followed by TLC on Alugram SIL G/UV254
silica gel sheets (Macherey-Nagel) with detection by UV or
with 0.5% phosphomolybdic acid solution in 95% EtOH. Silica
gel 60 (Macherey-Nagel 230 400 mesh) was used for flash
chromatography (FC). Melting points were determined with a
B¸chi 510 apparatus and are uncorrected. 1H NMR and
13C NMR spectra were recorded with Bruker AC-300 spec-
trometer. Infra-red spectroscopy was performed on a Perkin-
Elmer Spectrum One series FTIR apparatus.
32.0, 31.5, 28.9, 28.8, 22.5, 24.6, 14.0; MS (EI): m/z 371 (M ),
7-[(3-Cyano-3-acetoxy-prop-1-yl)oxy]-2H-1-
benzopyran-2-one (1a)
210, 162; HRMS: calcd. for C21H25NO5: 371.17327; found:
371.17337; anal. calcd. (%) for C21H25NO5: C 67.91, H 6.78;
found C 67.99, H 6.84.
Cyanohydrin 2 (100 mg, 0.045 mmol) was treated at 08C with
acetic anhydride (1 mL) and pyridine (0.05 mL). After 16 h at
208C, the reagents were removed by coevaporation with
toluene, and the crude product was purified by flash chroma-
tography (hexane/ethyl acetate 7:3) to give acetate 1a as a
colorless solid; yield: 104 mg (0.36 mmol, 95%); mp 818C; Rf
0.25 (hexane/EtOAc, 7/3); IR (CHCl3): n 3414, 2359, 1716,
7-[(3-Cyano-3-(pivaloyloxy)prop-1-yl)oxy]-2H-1-
benzopyran-2-one (1c)
To a solution of cyanohydrin 2 (11 mg, 0.045 mmol) in dry
dichloromethane (4 mL) were added pyvaloyl chloride (11 mL,
2 equivalents) and pyridine (7 mL, 2 equivalents) at 08C. The
reaction mixture was stirred overnight, extracted with EtOAc
(2 Â 10 mL), dried on Na2SO4 and evaporated. After a
chromatography column (hexane/EtOAc, 6/4, Rf 0.56), ester
1d was obtained as a colorless oil; yield: 13.7 mg (94%); IR
(CHCl3): n 2978, 1749, 1616, 1230 cmÀ1; 1H NMR (300 MHz,
CDCl3): d 7.65 (d, 1H, J 9.2 Hz), 7.40 (d, 1H, J 8.5 Hz),
6.86 (dd, 1H, J 8.5, 2.6 Hz), 6.81 (d, 1H, J 2.6 Hz), 6.29 (d,
1H, J 9.2 Hz), 5.61 (t, 1H, J 7.0 Hz), 4.20 (m, 2H), 2.49 (m,
2H), 1.24 (s, 9H); 13C NMR (50 MHz, CDCl3): d 177.1, 161.8,
161.6, 156.5, 143.9, 129.7, 117.2, 114.4, 113.8, 113.5, 102.1, 63.7,
1616, 1384, 1210, 829 cmÀ1; H NMR (300 MHz, CDCl3): d
1
7.66 (d, 1H, J 9.6 Hz), 7.46 (d, 1H, J 8.8 Hz), 6.85 (dd, 1H,
J 8.8, 2.2 Hz), 6.79 (d, 1H, J 2.2 Hz), 6.28 (d, 1H, J
9.6 Hz), 5.59 (t, 1H, J 6.6 Hz), 4.25 (m, 2H), 2.51 (m, 2H),
2.20 (s, 3H); 13C NMR (50 MHz, CDCl3): d 168.9, 161.1,
160.8, 155.7, 143.2, 128.9, 116.3, 113.6, 113.1, 112.8, 101.4, 62.9,
58.2, 32.0, 20.2; MS (EI): m/z 287 (M ), 162, 134, 126, 105, 43;
HRMS: calcd. for C15H13NO5: 287.07937; found: 287.07937;
anal. calcd. (%) for C15H13NO5: C 62.72, H 4.56; found: C 62.67,
H 4.54.
58.8, 39.6, 32.7, 27.6; MS (EI): m/z 329 (M ), 168, 162;
HRMS: calcd. for C18H19NO5: 329.12632; found: 329.12619;
anal. calcd. (%) for C18H19NO5: C 65.64, H 5.81; found C 65.37,
H 5.79.
7-[(3-(Butyryloxy)-3-cyanoprop-1-yl)oxy]-2H-1-
benzopyran-2-one (1b)
To a solution of cyanohydrin 2 (100 mg, 0.45 mmol) in dry
dichloromethane (4 mL), were added butanoyl chloride
(141 mL, 3 equivalents) and pyridine (108 mL, 3 equivalents)
at 08C. The reaction mixture was stirred overnight, extracted
with EtOAc (2 Â 10 mL), dried on Na2SO4 and evaporated.
Flash chromatography (hexane/EtOAc 6/4, Rf 0.31) gave
ester 1b as a colorless oil; yield: 105 mg (74%); Rf 0.31
(hexane/EtOAc, 6/4); IR (CHCl3): n 2973, 2881, 2401, 1732,
1615, 1216, 838 cmÀ1; 1H NMR (300 MHz, CDCl3): d 7.65 (d,
1H, H4, J 9.5 Hz), 7.40 (d, 1H, J 8.4 Hz), 6.85 (dd, 1H, J
8.4 Hz, J 2.2 Hz), 6.80 (d, 1H, J 2.2 Hz), 6.27 (d, 1H, J
9.6 Hz), 5.62 (t, 1H, J 7.0 Hz), 4.20 (m, 2H), 2.47 (m, 2H), 2.38
(t, 2H, J 7.4 Hz), 1.69 (qt, 2H, J 7.4, 7.4 Hz), 0.95 (t, 3H, J
7.4 Hz); 13C NMR (50 MHz, CDCl3): d 171.6, 161.1, 161.0,
155.7, 143.2, 128.9, 113.6, 113.0, 112.8, 101.3, 62.9, 57.9, 35.4,
7-[(3-Cyano-3-benzoyloxyprop-1-yl)oxy]-2H-1-
benzopyran-2-one (1e)
A solution of cyanohydrin 2 (100 mg, 0.045 mmol) in 4 mL
anhydrous CH2Cl2 at 08C was treated with pyridine (0.05 mL,
0.9 mmol) and benzoyl chloride (0.095 mL, 115 mg, 1.2 mmol).
The reaction mixture was stirred for 17 h at 208C. Aqueous
work-up (AcOEt) and flash chromatography (hexane/EtOAc,
6:4) of the organic residue gave benzoate ester 1d as a colorless
solid; yield: 125 mg (0.36 mmol, 88%); mp 1378C; Rf 0.5
(hexane/EtOAc, 6/4); IR (CHCl3): n 3414, 1732, 1613, 1259,
1124, 849 cmÀ1; 1H NMR (300 MHz, CDCl3): d 8.05 (m, 2H),
7.65 (d, 1H, J 9.6 Hz); 7.62 (m, 1H), 7.50 (m. 2H), 7.38 (d, 1H,
J 8.4 Hz), 6.85 (dd, 1H, J 2.6, 8.8 Hz), 6.79 (d, 1H, J
2.6 Hz), 6.24 (d, 1H, J 9.6 Hz), 5.86 (t, 1H, J 6.6 Hz), 4.29
(m, 2H), 2.31 (m, 2H); 13C NMR (50 MHz, CDCl3): d 165.3,
161.8, 161.6, 156.4, 143.9, 134.9, 130.6, 129.6, 129.4, 128.6, 117.1,
114.3, 113.8, 113.5, 102.1, 63.8, 59.5, 32.9; HRMS: calcd for
32.0, 18.1, 13.4; MS (EI): m/z 315 (M ), 162, 154; HRMS:
calcd. for C17H17NO5: 315.110530; found: 315.110673; anal.
calcd. (%) for C17H17NO5: C 64.75, H 5.43; found C 64.71, H
5.37.
864
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Adv. Synth. Catal. 2003, 345, 859 865