Oxidation of 2ꢀacetylcyclopentanone with oxygen
Russ.Chem.Bull., Int.Ed., Vol. 61, No. 6, June, 2012
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with a hexane—acetone (35 : 1) mixture gave 0.25 g (20%) of the
max/cm–1: 3520 (ОН), 3476 (ОН), 1755 (C=O), 1747 (C=O),
starting diketone 1 as a colorless mobile liquid. IR, max/cm–1
:
1718 (C=O), 1711 (C=O), 1405, 1356, 1315, 1232, 1209, 1158,
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3530—2400 (ОН), 1744 (C=O), 1709 (С=О), 1660 (C=O), 1610
1092, 1049, 1026. Н NMR (CDCl3), : 1.94—2.05 (m, 1 Н,
(C=O, C=C), 1588 (C=О, C=C), 1451, 1405, 1387, 1360, 1285,
1239, 1197, 1180, 1139, 1121. Н NMR (CDCl3), for enol
Н(3)); 2.06—2.20 (m, 2 Н, 2 H(4)); 2.23 (s, 3 Н, СОМе);
2.40—2.50 (m, 3 Н, Н(3), 2 H(5)); 3.93 (br.s, 1 Н, ОН).
13С NMR (CDCl3), : 18.4 (C(4)); 25.7 (C(7)); 34.7 (C(3)); 36.0
(C(5)); 86.3 (C(2)); 207.2 (C(6)); 215.2 (C(1)). MS (EI, 70 eV),
m/z (Irel (%)): 142 [М]+ (7), 125 (5), 124 (2), 115 (16), 114 (22),
100 (39), 99 (28), 88 (10), 87 (34), 86 (100), 85 (25), 83 (10),
74 (10), 73 (37), 71 (44), 70 (13), 69 (12), 60 (76), 58 (45),
57 (23), 55 (88), 46 (39), 45 (13), 44 (94), 43 (47), 42 (34), 40 (18),
32 (53), 31 (30).
Elution with a hexane—acetone (7 : 1) mixture gave 0.022 g
(2%) of 2ꢀacetylꢀ2,3ꢀepoxycyclopentanone (5) as a colorless visꢀ
cous oil. IR, max/cm–1: 1754 (C=O), 1710 (C=O), 1446, 1411,
1389, 1360, 1301, 1284, 1257, 1216, 1165, 1072, 1040. 1Н NMR
(CDCl3), : 2.14 (m, 1 Н, Н(4)); 2.23 (m, 2 Н, 2 H(5)); 2.28
(s, 3 Н, СОМе); 2.38 (m, 1 Н, Н(4)); 4.11 (br.s, 1 Н, H(3),
J = 2.2 Hz). 13С NMR (CDCl3), : 22.7 (C(4)); 28.3 (C(7));
32.8 (C(5)); 63.9 (C(2)); 65.8 (C(3)); 199.5 (C(6)); 204.6
(C(1)). MS (EI, 70 eV), m/z (Irel (%)): 140 [М]+ (15), 126 (22),
125 (29), 124 (25), 111 (16), 109 (31), 98 (8), 97 (11), 96 (11),
85 (16), 81 (7), 57 (17), 55 (34), 45 (25), 44 (63), 43 (14), 42 (22),
32 (100).
Elution with a hexane—acetone (5 : 1) mixture gave 0.062 g
(5%) of 2ꢀacetylꢀ2ꢀhydroxymethylcyclopentanone (3) as a colorꢀ
less oil. IR, max/cm–1: 3612 (ОН), 3519 (ОН), 1739 (C=O),
1708 (C=O), 1406, 1358, 1318, 1276, 1243, 1149, 1060. 1Н NMR
(CDCl3), : 1.96 (m, 1 Н, Н(4)); 1.98 (m, 1 Н, Н(3)); 2.01
(m, 1 Н, H(5)); 2.23 (s, 3 Н, СОМе); 2.26 (m, 1 Н, Н(4));
2.37 (m, 1 Н, Н(3)); 2.43 (m, 1 Н, Н(5)); 3.84 (d, 1 Н, Н(8),
J = 11.3 Hz); 3.91 (d, 1 Н, Н(8), J = 11.3 Hz). 13С NMR
(CDCl3), : 19.8 (C(4)); 27.1 (C(7)); 29.8 (C(3)); 39.1 (C(5));
64.8 (C(8)); 69.8 (C(2)); 205.8 (C(6)); 216.9 (C(1)). MS (EI,
70 eV), m/z (Irel (%)): 156 [М]+ (11), 139 (7), 138 (15), 115 (30),
114 (12), 111 (13), 110 (15), 97 (25), 96 (96), 95 (26), 87 (44),
68 (77), 67 (25), 55 (42), 46 (31), 44 (100), 43 (26), 42 (43).
Found (%): С, 61.61; Н, 7.78. С8Н12О3. Calculated (%):
С, 61.52; Н, 7.74.
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form 1B (1C): 1.91 (quint, 2 Н, 2 H(4), J = 7.1 Hz); 1.99 (s, 3 Н,
С(6)Ме); 2.41 (t, 2 Н, 2 H(5), J = 7.1 Hz); 2.55 (t, 2 Н, 2 H(3),
J = 7.1 Hz); 13.50 (br.s, 1 Н, ОН). 13С NMR (CDCl3), for
enol form 1B (1C): 20.1 (C(4)); 20.6 (C(7)); 25.7 (C(3)); 36.8
(C(5)); 109.7 (C(2)); 175.7 (C(6)); 204.9 (C(1)). 1Н NMR
(CDCl3), for diketo form 1A: 1.87 (m, 1 Н, Н(4)); 2.06 (m, 2 Н,
Н(3), Н(4)); 2.25 (m, 1 Н, Н(5)); 2.29 (m, 1 Н, Н(5)); 2.32
(s, 3 Н, СОМе); 2.42 (m, 1 Н, Н(3)); 3.39 (dd, 1 Н, Н(2),
J = 5.7 Hz, J = 8.1 Hz). 13С NMR (CDCl3), for diketo form 1A:
20.5 (C(4)); 25.0 (C(3)); 30.0 (C(7)); 38.6 (C(5)); 62.6 (C(2));
202.3 (C(6)); 212.7 (C(1)).
Elution with a hexane—acetone (30 : 1) mixture gave 0.22 g
(11%) of 1,1´ꢀdiacetylꢀ1,1´ꢀbicyclopentylꢀ2,2´ꢀdione (4) as a colꢀ
orless viscous oil. IR, max/cm–1: 1753 (С=О), 1712 (C=O),
1465, 1440, 1419, 1403, 1359, 1316, 1275, 1226, 1152, 1127.
1Н NMR (CDCl3), : 2.00—2.15 (m, 2 H, 2 H(4)); 2.16—2.31
(m, 1 H, H(3)); 2.33—2.40 (m, 1 H, H(5)); 2.47 (s, 3 Н, СОМе);
2.48—2.59 (m, 1 H, H(5)); 2.76—2.87 (m, 1 H, H(3)). 13С NMR
(CDCl3), : 18.9 (C(4)); 27.5 (C(7)); 36.3 (C(5)); 36.6 (C(3));
74.2 (C(2)); 201.9 (C(6)); 208.1 (C(1)). MS (EI, 15 eV), m/z
(Irel (%)): 250 [М]+ (5), 208 [М]+ – 42 (28), 207 [М]+ – 43 (7),
125 (40), 83 (37), 42 (100). Found (%): С, 67.29; Н, 7.21.
C14H18O4. Calculated (%): С, 67.18; Н, 7.25.
Elution with a hexane—acetone (25 : 1) mixture gave 0.007 g
(~1%) of 1,3,5ꢀtrioxane (9). Colorless crystals, m.p. 62—63 С.
1Н NMR (CDCl3), : 5.14 (s, 6 Н, 3 СН2). 13С NMR (CDCl3),
: 95.4 (C(2), C(4), C(6)). MS (EI, 15 eV), m/z (Irel (%)): 90
[М]+ (6), 30 (100).
Elution with a hexane—acetone (20 : 1) mixture gave 0.064 g
(7%) of glutaric anhydride (7). Colorless crystals, m.p. 51—54 С.
IR, max/cm–1: 1748 (C=O), 1715 (С=О), 1602, 1451, 1415,
1290, 1240, 1132. 1Н NMR (CDCl3), : 2.02 (quint, 2 Н, 2 H(4),
J = 6.8 Hz); 2.75 (t, 4 Н, 2 H(3), 2 H(5), J = 6.8 Hz). 13С NMR
(CDCl3), : 16.7 (C(4)); 30.3 (C(3), C(5)); 166.8 (C(2), C(6)).
Elution with a hexane—acetone (15 : 1) mixture gave 0.014 g
Elution with a hexane—acetone (4 : 1) mixture gave 0.014 g
of 4ꢀhydroxyꢀ4ꢀmethylpentanꢀ2ꢀone (diacetone alcohol, 10). Colꢀ
(2%) of ꢀbutyrolactone (8). Colorless liquid, [n]D20 1.4351. IR,
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20
max/cm–1: 1772 (C=O). Н NMR (CDCl3), : 2.23 (m, 2 Н,
orless labile liquid, [n]D 1.4232. IR, max/cm–1: 3540 (ОН),
2 H(4)); 2.45 (m, 2 Н, 2 H(3)); 4.35 (t, 2 Н, 2 H(5), J = 7.1 Hz).
13С NMR (CDCl3), : 22.2 (C(4)); 27.8 (C(3)); 68.5 (C(5));
177.8 (C(2)).
1710 (C=O), 1542, 1508, 1457, 1389, 1377, 1362, 1325, 1175,
1146, 1017. 1Н NMR (CDCl3), : 1.21 (s, 6 Н, 2 C(4)Me); 1.79
(br.s, 1 H, OH); 2.14 (s, 3 Н, СОМе); 2.60 (s, 2 Н, CH2).
13С NMR (CDCl3), : 29.5 (C(5), С(6)); 32.1 (C(1)); 54.2 (C(3));
69.7 (C(4)); 211.3 (C(2)).
Elution with a hexane—acetone (10 : 1) mixture gave 0.023 g
(2%) of 2ꢀacetoxycyclopentanone (6) as a colorless oil. IR,
max/cm–1: 1756 (C=O), 1718 (C=O), 1405, 1356, 1232, 1209,
An aqueous soda solution (60 mL) remained after washing of
the organic extract was acidified with 2 М HCl to pH 1.0, and
the reaction products were extracted with chloroform (5×10 mL).
The combined organic extracts were washed with a saturated
aqueous solution of NaCl (4×5 mL) and dried above Na2SO4.
The solvent was removed and the unpurified product was chroꢀ
matographed on a column with SiO2. Elution with a hexꢀ
ane—acetone (6 : 1) mixture gave 0.164 g (13%) of 5,6ꢀdioxoꢀ
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1158, 1092, 1049. Н NMR (CDCl3), : 1.87—2.13 (m, 2 Н,
2 Н(4)); 2.14 (s, 3 Н, OAc); 2.09—2.19 (m, 2 Н, 2 Н(5));
2.16—2.27 (m, 2 Н, 2 Н(3)); 5.05 (m, 1 Н, H(2), J = 8.1 Hz,
J = 4.1 Hz, J = 3.8 Hz, J = 2.2 Hz). 13С NMR (CDCl3), : 17.2
(C(4)); 20.9 (C(7)); 28.5 (C(3)); 34.4 (C(5)); 75.8 (C(2)); 170.4
(C(6)); 215.0 (C(1)). MS (EI, 70 eV), m/z (Irel (%)): 142 [М]+
(10), 100 (100), 99 (85), 98 (21), 83 (6), 82 (17), 73 (6), 72 (16),
71 (34), 60 (14), 55 (18), 44 (39).
heptanoic acid (11). Viscous light yellow oil. IR, max/cm–1
:
Elution with a hexane—acetone (8 : 1) mixture gave 0.43 g
(38%) of 2ꢀacetylꢀ2ꢀhydroxycyclopentanone (2) as a colorless
viscous oil (cf. Ref. 26: yellow oil; Ref. 27: white solid, m.p.
58—59 С). IR (CHCl3), max/cm–1: 3511 (ОН), 1753 (C=O),
1711 (C=O), 1402, 1360, 1227, 1157, 1092, 1048. IR (CCl4),
3400—2400 (СООН), 1745 (C=O), 1714 (C=O), 1417, 1358,
1239, 1133, 1046. 1Н NMR (CDCl3), : 1.94 (quint, 2 Н, 2 Н(3),
J = 7.2 Hz); 2.34 (s, 3 Н, СОМе); 2.43 (t, 2 Н, 2 Н(2),
J = 7.2 Hz); 2.85 (t, 2 Н, 2 Н(4), J = 7.2 Hz); 9.82 (br.s, 1 Н,
СООН). 13С NMR (CDCl3), : 18.3 (C(3)); 24.0 (C(7)); 33.0