O. Khoumeri et al. / Tetrahedron 64 (2008) 11237–11242
11241
147.7, 147.8, 152.2, 155.4, 181.5, 182.5. Anal. Calcd for C24H19NO7: C,
66.51; H, 4.42; N, 3.23. Found: C, 66.18; H, 4.54; N, 3.19.
OCH3), 4.27 (d, J¼1.8 Hz,1H, CH), 7.27 (s,1H, Ar-H), 7.48 (d, J¼8.1 Hz,
2H, Ar-H), 7.68 (d, J¼8.1 Hz, 2H, Ar-H), 7.70–7.78 (m, 2H, Ar-H),
8.10–8.18 (m, 2H, Ar-H). 13C NMR (50 MHz, CDCl3) dC 56.8, 58.6, 61.6,
62.4, 112.5, 114.5, 118.3, 122.3, 126.2, 126.3, 126.6, 127.3, 132.6, 133.3,
133.6, 133.8, 134.2, 139.4, 141.3, 152.3, 157.1, 182.5, 183.0. cis-isomer:
yellow solid; mp 175 ꢁC; 1H NMR (200 MHz, CDCl3) dH 3.87 (s, 3H,
OCH3), 3.93 (s, 3H, OCH3), 4.58 (d, J¼4.4 Hz, 1H, CH), 4.68 (d,
J¼4.4 Hz,1H, CH), 7.18 (s, 1H, Ar-H), 7.37 (d, J¼8.3, 2H, Ar-H), 7.50 (d,
J¼8.3, 2H, Ar-H), 7.67–7.78 (m, 2H, Ar-H), 8.10–8.21 (m, 2H, Ar-H).
13C NMR (50 MHz, CDCl3) dC 56.8, 57.2, 59.4, 62.1, 112.1, 117.8, 126.3,
126.6, 127.2, 127.3, 127.8, 131.9, 132.5, 133.3, 133.5, 133.8, 134.2,
136.8, 138.9, 152.4, 156.0, 182.5, 182.9. Anal. Calcd for C25H17NO5: C,
72.99; H, 4.16; N, 3.40. Found: C, 72.68; H, 4.20; N, 3.45.
4.2. General procedure for TDAE reaction of 2 with
aromatic aldehydes
Into a two-necked flask equipped with a silica gel drying tube
and a nitrogen inlet were added, under nitrogen at ꢀ20 ꢁC, 10 mL of
anhydrous DMF solution of 2 (0.2 g, 0.45 mmol) and aldehyde 3a–j
(0.90 mmol, 2 equiv). The solution was stirred and maintained at
this temperature for 30 min and then was added dropwise (via
a syringe) TDAE (0.157 mL, 0.675 mmol, 1.5 equiv). A red color im-
mediately developed with the formation of a white fine precipitate.
The solution was vigorously stirred at ꢀ20 ꢁC for 1 h and
then warmed up to rt for 2 h. After this time TLC analysis
(dichloromethane) clearly showed that 2 was totally consumed.
The orange-red turbid solution was filtered (to remove the octa-
methyloxamidinium dibromide) and hydrolyzed with 80 mL of
H2O. The aqueous solution was extracted with toluene (3ꢂ40 mL),
the combined organic layers washed with H2O (3ꢂ40 mL), and
dried over MgSO4. Evaporation of the solvent left an orange viscous
liquid as crude product. Purification by silica gel chromatography
(dichloromethane/Et2O, 98/2) gave the corresponding mixture of
cis/trans-isomer oxiranes 5a–j as solids.
4.2.4. 1,4-Dimethoxy-2-(3-phenyloxiran-2-yl)anthracene-9,10-
dione (5d)
trans-isomer: yellow solid; mp 183 ꢁC; 1H NMR (200 MHz,
CDCl3) dH 3.81 (d, J¼1.8 Hz, 1H, CH), 3.85 (s, 3H, OCH3), 4.04 (s, 3H,
OCH3), 4.34 (d, J¼1.8 Hz, 1H, CH), 7.31 (s, 1H, Ar-H), 7.36–7.45 (m,
5H, Ar-H), 7.70–7.74 (m, 2H, Ar-H), 8.13–8.21 (m, 2H, Ar-H). 13C NMR
(50 MHz, CDCl3) dC 56.8, 58.2, 60.4, 62.8, 114.7, 122.0, 125.6, 126.3,
126.7, 127.4, 128.7, 128.8, 133.3, 133.7, 133.8, 134.4, 136.0, 140.6,
152.4, 157.2, 182.6, 183.2. cis-isomer: yellow solid; mp 218 ꢁC; 1H
NMR (200 MHz, CDCl3) dH 3.88 (s, 3H, OCH3), 4.00 (s, 3H, OCH3),
4.57 (d, J¼4.5 Hz, 1H, CH), 4.66 (d, J¼4.5 Hz, 1H, CH), 7.16 (s, 1H, Ar-
H), 7.18–7.25 (m, 5H, Ar-H), 7.67–7.76 (m, 2H, Ar-H), 8.10–8.18 (m,
2H, Ar-H). 13C NMR (50 MHz, CDCl3) dC 56.6, 56.7, 60.3, 62.0, 118.2,
121.7,126.5,126.7,128.1,128.7,128.8,133.2,133.6,133.7,133.9,134.0,
134.3, 137.9, 142.4, 152.6, 155.9, 156.3, 182.8, 183.6. Anal. Calcd for
C24H18O5: C, 74.60; H, 4.70. Found: C, 74.30; H, 5.18.
4.2.1. 1,4-Dimethoxy-2-[3-(4-nitrophenyl)oxiran-2-yl]-anthracene-
9,10-dione (5a)
trans-isomer: yellow solid; mp 202 ꢁC; 1H NMR (200 MHz,
CDCl3) dH 3.86 (s, 3H, OCH3), 3.92 (d, J¼1.7 Hz, 1H, CH), 4.06 (s, 3H,
OCH3), 4.31 (d, J¼1.7 Hz,1H, CH), 7.31 (s,1H, Ar-H), 7.55 (d, J¼8.8 Hz,
2H, Ar-H), 7.72–7.77 (m, 2H, Ar-H), 8.14–8.20 (m, 2H, Ar-H), 8.28 (d,
J¼8.8 Hz, 2H, Ar-H). 13C NMR (50 MHz, CDCl3) dC 56.9, 58.8, 61.5,
62.6, 114.6, 122.5, 124.2, 126.4, 126.5, 126.7, 127.5, 133.5, 133.7, 133.9,
134.3, 139.4, 143.2, 148.2, 152.4, 157.2, 182.6, 183.1. cis-isomer: yel-
low solid; mp 248 ꢁC; 1H NMR (200 MHz, CDCl3) dH 3.89 (s, 3H,
OCH3), 3.94 (s, 3H, OCH3), 4.62 (d, J¼4.4 Hz, 1H, CH), 4.70 (d,
J¼4.4 Hz, 1H, CH), 7.21 (s, 1H, Ar-H), 7.44 (d, J¼8.8 Hz, 2H, Ar-H),
7.67–7.71 (m, 2H, Ar-H), 8.06 (d, J¼8.8 Hz, 2H, Ar-H), 8.09–8.14 (m,
2H, Ar-H). 13C NMR (50 MHz, CDCl3) dC 56.8, 57.3, 59.2, 62.1, 117.8,
122.3, 123.4, 124.2, 126.3, 126.6, 126.9, 127.4, 133.3, 133.4, 133.8,
134.2, 136.7, 140.9, 147.7, 152.4, 156.0, 182.5, 182.9. Anal. Calcd for
C24H17NO7: C, 66.82; H, 3.97; N, 3.25. Found: C, 66.76; H, 4.16; N,
3.25.
4.2.5. 1,4-Dimethoxy-2-(3-p-tolyloxiran-2-yl)anthracene-9,10-
dione (5e)
trans-isomer: yellow solid; mp 188 ꢁC; 1H NMR (200 MHz,
CDCl3) dH 2.38 (s, 3H, CH), 3.76 (d, J¼1.7 Hz, 1H, CH), 3.84 (s, 3H,
OCH3), 4.03 (s, 3H, OCH3), 4.32 (d, J¼1.7 Hz,1H, CH), 7.23 (m, 2H, Ar-
H), 7.25 (s, 1H, Ar-H), 7.30 (m, 2H, Ar-H), 7.69–7.74 (m, 2H, Ar-H),
8.12–8.20 (m, 2H, Ar-H). 13C NMR (50 MHz, CDCl3) dC 21.2, 56.8, 58.1,
62.4, 62.9, 114.6, 121.9, 125.6, 126.3, 126.6, 127.3, 129.4, 133.0, 133.2,
133.7, 133.8, 134.4, 138.7, 140.8, 152.3, 157.2, 182.6, 183.2. cis-isomer:
yellow solid; mp 179 ꢁC; 1H NMR (200 MHz, CDCl3) dH 2.23 (s, 3H,
CH3), 3.87 (s, 3H, OCH3), 3.89 (s, 3H, OCH3), 4.54 (d, J¼3.7 Hz, 1H,
CH), 4.64 (d, J¼3.7 Hz, 1H, CH), 7.00 (d, J¼8.1 Hz, 2H, Ar-H), 7.14 (d,
J¼8.1 Hz, 2H, Ar-H), 7.17 (s, 1H, Ar-H), 7.66–7.71 (m, 2H, Ar-H), 8.10–
8.14 (m, 2H, Ar-H). 13C NMR (50 MHz, CDCl3) dC 21.1, 56.7, 56.8, 60.4,
62.1, 118.2, 121.6, 126.3, 126.5, 126.6, 126.7, 128.8, 130.4, 133.2, 133.6,
133.7, 134.3, 137.9, 138.2, 152.7, 155.9, 182.8, 183.1. Anal. Calcd for
C25H20O5: C, 74.99; H, 5.03. Found: C, 74.09; H, 5.50.
4.2.2. 2-[3-(4-Bromophenyl)oxiran-2-yl]-1,4-
dimethoxyanthracene-9,10-dione (5b)
trans-isomer: yellow solid; mp 227 ꢁC; 1H NMR (200 MHz,
CDCl3) dH 3.77 (d, J¼1.7 Hz, 1H, CH), 3.85 (s, 3H, OCH3), 4.04 (s, 3H,
OCH3), 4.28 (d, J¼1.7 Hz, 1H, CH), 7.25 (d, J¼8.4 Hz, 2H, Ar-H), 7.29
(s, 1H, Ar-H), 7.55 (d, J¼8.4 Hz, 2H, Ar-H), 7.70–7.76 (m, 2H, Ar-H),
8.13–8.21 (m, 2H, Ar-H). 13C NMR (50 MHz, CDCl3) dC 56.8, 58.3, 62.1,
62.5, 114.6, 122.1, 122.8, 126.4, 126.7, 127.2, 127.4, 132.0, 133.3, 133.7,
133.8, 134.3, 135.1, 140.1, 152.3, 157.2, 182.6, 183.2. cis-isomer: yellow
solid; mp 175 ꢁC; 1H NMR (200 MHz, CDCl3) dH 3.87 (s, 3H, OCH3),
3.91 (s, 3H, OCH3), 4.51 (d, J¼4.4 Hz, 1H, CH), 4.65 (d, J¼4.4 Hz, 1H,
CH), 7.13 (d, J¼8.5 Hz, 2H, Ar-H), 7.16 (s, 1H, Ar-H), 7.34 (d, J¼8.5 Hz,
2H, Ar-H), 7.67–7.72 (m, 2H, Ar-H), 8.10–8.16 (m, 2H, Ar-H). 13C NMR
(50 MHz, CDCl3) dC 56.8, 56.9, 59.7, 62.1, 118.0, 122.0, 122.2, 126.4,
126.6, 126.8, 128.3, 131.3, 132.6, 133.3, 133.6, 133.7, 134.3, 137.5,
152.6, 156.0, 182.6, 183.1. Anal. Calcd for C24H17BrO5: C, 61.95; H,
3.68. Found: C, 61.60; H, 3.76.
4.2.6. 2-[3-(4-Chlorophenyl)oxiran-2-yl]-1,4-
dimethoxyanthracene-9,10-dione (5f)
trans-isomer: yellow solid; mp 218 ꢁC; 1H NMR (200 MHz,
CDCl3) dH 3.78 (d, J¼1.8 Hz, 1H, CH), 3.85 (s, 3H, OCH3), 4.03 (s, 3H,
OCH3), 4.28 (d, J¼1.8 Hz,1H, CH), 7.28 (s,1H, Ar-H), 7.31 (d, J¼8.5 Hz,
2H, Ar-H), 7.39 (d, J¼8.5 Hz, 2H, Ar-H), 7.70–7.77 (m, 2H, Ar-H),
8.12–8.20 (m, 2H, Ar-H). 13C NMR (50 MHz, CDCl3) dC 56.8, 58.3,
62.1, 62.4, 114.6, 122.1, 126.4, 126.7, 127.0, 127.4, 129.0, 133.3, 133.7,
133.8, 134.4, 134.6, 134.7, 140.2, 152.3, 157.2, 182.6, 183.2. cis-isomer:
yellow solid; mp 184 ꢁC; 1H NMR (50 MHz, CDCl3) dH 3.87 (s, 3H,
OCH3), 3.90 (s, 3H, OCH3), 4.52 (d, J¼4.4 Hz, 1H, CH), 4.63 (d,
J¼4.4 Hz,1H, CH), 7.15 (s,1H, Ar-H), 7.18 (m, 4H, Ar-H), 7.66–7.71 (m,
2H, Ar-H), 8.08–8.14 (m, 2H, Ar-H). 13C NMR (50 MHz, CDCl3) dC
56.7, 56.8, 59.6, 62.0, 118.0, 121.9, 126.3, 126.6, 126.8, 127.9, 128.4,
132.0, 133.2, 133.6, 133.7, 134.0, 134.3, 137.5, 152.5, 155.9, 182.6,
183.0. Anal. Calcd for C24H17ClO5: C, 68.50; H, 4.07. Found: C, 68.31;
H, 4.09.
4.2.3. 4-[3-(9,10-Dihydro-1,4-dimethoxy-9,10-dioxo-anthracen-2-
yl)oxiran-2-yl]benzonitrile (5c)
trans-isomer: yellow solid; mp 234 ꢁC; 1H NMR (200 MHz,
CDCl3) dH 3.83 (s, 3H, OCH3), 3.86 (d, J¼1.8 Hz, 1H, CH), 4.02 (s, 3H,