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SZANTO ET AL.
1122
4-(3-Methoxyphenyl)-5-nitro-pentane-2-one (6a)
4-(4-Hidroxy-3-methoxyphenyl)-5-nitro-
pentane-2-one (6e)
20
Yield: 68%; ½aꢀD : 21.28 (c 5 1, CHCl3), 74% ee. The
20
enantiomer excess was determined by HPLC analysis with
Yield: 55%; ½aꢀD : 20.58 (c 5 1, CHCl3), 67% ee. The
Chiralcel OD (Daicel Chemical Industries); eluent: hex- enantiomer excess was determined by HPLC analysis with
ane:isopropanol 5 8:2; flow rate: 1 ml/min; detection: UV Chiralpak AD (Daicel Chemical Industries); eluent: hex-
286 nm; temperature: 208C. Oil. 1H NMR (500 MHz, ane:isopropanol 5 9:1; flow rate: 1 ml/min; detection: UV
CDCl3): d 2.05 (s, 3H, 1-CH3), 2.83 (d, 2H, 3-CH2), 3.72 (s, 224 nm; temperature: 58C, mp. 66–688C. 1H NMR
3H, OCH3); 3.91 (kv, 1H, 4-CH), 4.50-4.62 (m, 2H, 5-CH2), (500 MHz, CDCl3): d 2.13 (s, 3H, 1-CH3), 2.89 (d, 2H, 3-
6.67–6.74 (m, 3H, Ar-CH), 7.17 (t, 1H, Ar-CH); 13C-NMR CH2), 3.89 (s, 3H, OCH3), 3.94 (kv, 1H, 4-CH), 4.53–4.69
(75 MHz, CDCl3): d 30.6, 39.3, 46.3, 55.4, 79.6, 113.1, (m, 2H, 5-CH2), 5.59 (s, 1H, OH), 6.69-6.88 (m, 3H, Ar-
113.8, 119.7, 130.3, 140.6, 160.2, 205.5; HRMS calcd for CH); 13C NMR (75 MHz, CDCl3): d 30.7, 39.1, 46.6, 56.2,
C12H15NO4 (M1) 237.1001, found 237.1004.
80.0, 110.7, 115.0, 119.8, 130.9, 145.5, 146.9, 205.7; HRMS
calcd for C12H15NO5 (M1) 253.0950, found 253.0955.
4-(4-Benzyloxy-3-methoxyphenyl)-5-nitro-
pentane-2-one (6f)
4-(3,4-Dimethoxyphenyl)-5-nitro-pentane-2-one (6b)
20
Yield: 49%; ½aꢀD : 21.28 (c 5 1, CHCl3), 82% ee. The
20
Yield: 55%; ½aꢀD : 11.58 (c 5 1, CHCl3), 71% ee. The
enantiomer excess was determined by HPLC analysis with
Chiralcel OD (Daicel Chemical Industries); eluent: hex-
ane:isopropanol 5 8:2; flow rate: 1 ml/min; detection: UV
286 nm; temperature: 58C, mp. 76–788C, Reichert and Pose-
mann gave 90–918C (from methanol) for the pure racemic
6b.70,71 1H NMR (500 MHz, CDCl3): d 2.05 (s, 3H, 1-CH3),
2.82 (d, 2H, 3-CH2), 3.78 (s, 3H, OCH3), 3.80 (s, 3H,
OCH3), 3.88 (kv, 1H, 4-CH), 4.51–4.59 (m, 2H, 5-CH2),
6.65-6.75 (m, 3H, Ar-CH); 13C NMR (75 MHz, CDCl3): d
30.6, 39.0, 46.5, 56.1, 56.2, 79.9, 111.1, 111.7, 119.4, 131.5,
148.8, 149.4, 205.7; HRMS calcd for C13H17NO5 (M1)
267.1107, found 267.1113.
enantiomer excess was determined by HPLC analysis with
Chiralcel OD (Daicel Chemical Industries); eluent: hex-
ane:isopropanol 5 8:2; flow rate: 1 ml/min; detection: UV
1
210 nm; temperature: 308C, 91–938C. H-NMR (500 MHz,
CDCl3): d 2.03 (s, 3H, 1-CH3), 2.79 (d, 2H, 3-CH2), 3.80 (s,
3H, OCH3), 3.85 (kv, 1H, 4-CH), 4.45-4.60 (m, 2H, 5-CH2),
5.03 (s, 2H, OꢁꢁCH2ꢁꢁPh), 6.58-6.76 (m, 3H, Ar-CH),
7.18–7.35 (m, 5H, Ar-CH); 13C-NMR (75 MHz, CDCl3): d
30.5, 38.8, 46.4, 56.2, 71.1, 79.7, 111.6, 114.3, 119.2, 127.3,
127.9, 128.6, 131.9, 137.0, 147.9, 150.0, 205.5; HRMS calcd
for C19H21NO5 (M1) 343.1420, found 343.1427.
Single Crystal X-Ray Diffraction
The crystals of 3,4-methylenedioxy-phenyl-5-nitro-pen-
tan-2-one are colorless platelets. The size of the crystal
selected for single crystal X-ray diffraction measurement is
0.40 3 0.35 3 0.10 mm. Formula is C12H13NO5, formula
weight is 251.23, F(000) 5 528. It crystallizes in the ortho-
rhombic crystal system, space group P212121. The cell
4-(3,4,5-Trimethoxyphenyl)-5-nitro-pentane-2-one (6c)
20
Yield: 72%; ½aꢀD : 21.38 (c 5 1, CHCl3), 80% ee. The
enantiomer excess was determined by HPLC analysis with
Chiralcel OD (Daicel Chemical Industries); eluent: hex-
ane:isopropanol 5 8:2; flow rate: 1 ml/min; detection: UV
210 nm; temperature: 208C, mp. 70–728C. 1H-NMR (500
MHz, CDCl3): d 2.07 (s, 3H, 1-CH3), 2.82 (d, 2H, 3-CH2),
3.74 (s, 3H, OCH3), 3.77 (s, 6H, 2xOCH3), 3.87 (kv, 1H, 4-
CH), 4.50–4.63 (m, 2H, 5-CH2), 6.34 (s, 2H, Ar-CH); 13C
NMR (75 MHz, CDCl3): d 30.6, 39.5, 46.5, 56.4, 61.0, 79.6,
104.7, 134.7, 137.8, 153.7, 205.5; HRMS calcd for
C14H19NO6 (M1) 297.1212, found 297.1206.
˚
˚
dimensions are a 5 5.6021(11) A, b 5 7.7172(13) A, c 5
3
˚
27.479(6) A, a 5 b 5 g 5 908, V 5 1188.0(4)A , Z 5 4,
Dx 5 1.405 mgm23. A crystal was mounted on a loop in
oil. The diffraction measurement was performed at T 5
101(1) K. Intensity data were collected on a Rigaku R-Axis
Rapid diffractometer (graphite monochromator; Mo-Ka
˚
radiation, k 5 0.71073 A) in the range 3.0 ꢂ y ꢂ 27.48.
Cell parameters were determined by least-squares of the
setting angles of all collected reflections. A total of 45124
reflections were collected of which 2704 were unique
[R(int) 5 0.094, R(r) 5 0.0409]; 2576 reflections were
4-(3,4-Methylenedioxy-phenyl)-5-nitro-
pentane-2-one (6d)
20
Yield: 52%; ½aꢀD : 22.18 (c 5 1, CHCl3), 100% ee. The >2r(I). Completeness to 2y 5 0.998. An empirical absorp-
enantiomer excess was determined by HPLC analysis with tion correction was applied to the data, l 5 0.111 mm21
,
Chiralcel OD (Daicel Chemical Industries); eluent: hex- the minimum and maximum transmission factors were
ane:isopropanol 5 8:2; flow rate: 1 ml/min; detection: UV 0.9571 and 0.9890. The structure was solved by direct
286 nm; temperature: 58C, mp. 100–1028C, Walker gave methods with SHELXS97.81 Neutral atomic scattering fac-
96.5–98.58C (from methanol) for the pure racemic 6d.61–69 tors and anomalous scattering factors are taken from Inter-
1H NMR (500 MHz, CDCl3): d 2.05 (s, 3H, 1-CH3), 2.79 (d, national Tables for X-ray Crystallography.82 Anisotropic
2H, 3-CH2), 3.85 (kv, 1H, 4-CH), 4.43–4.60 (m, 2H, 5-CH2), full-matrix least-squares refinement with SHELXL9783,84
5.87 (s, 2H, OꢁꢁCH2ꢁꢁO), 6.59–6.69 (m, 3H, Ar-CH); 13C on F2 for all nonhydrogen atoms yielded R1 5 0.0344 and
NMR (75 MHz, CDCl3): d 30.6, 39.1, 46.5, 79.9, 101.5, wR2 5 0.0891 for 2576 [I > 2r(I)], R1 5 0.0364 and wR2
107.9, 108.9, 120.9, 132.7, 147.4, 148.4, 205.5; HRMS calcd 5 0.0906 for all (2704) intensity data (goodness-of-fit 5
for C12H13NO5 (M1) 251.0794, found 251.0801.
1.032; the maximum and mean shift/esd 0.000 and 0.000).
Chirality DOI 10.1002/chir