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S. Muthusamy et al. / Tetrahedron 56 (2000) 6307±6318
was allowed to react with a benzene solution (3 ml) of diazo
ketone 14b (75 mg, 0.3 mmol) for 8 h at re¯ux according to
the general method B to afford 98 mg (82%) of 15b as a
white solid, mp 204±2068C (ethyl acetate/hexane); [Found:
C, 67.61; H, 6.13; N, 3.20. C24H27NO6 requires C, 67.75; H,
6.39; N, 3.29%]; nmax (KBr) 2941, 1779, 1740, 1714, 1389,
1319, 1214, 1078, 1012, 996 cm21; dH (200 MHz, CDCl3)
7.48±7.36 (3H, m, Arom-H), 7.29±7.23 (2H, m, Arom-H),
4.38 (2H, q, J 7.2 Hz, OCH2), 3.87 (1H, d, J8.2 Hz),
3.57 (1H, d, J 8.2 Hz), 2.91 (1H, dd, J114.2 Hz,
J27.4 Hz), 2.32±2.08 (5H, m), 1.76±1.30 (4H, m), 1.34
(3H, t, J7.2 Hz, CH2CH3), 1.03±0.97 (2H, m), 0.92 (3H,
t, J7.5 Hz, CH3); dC (50 MHz, CDCl3) 198.0 (CvO),
175.1 (NCO), 172.5 (NCO), 169.8 (COO), 132.1 (quat-C),
130.1 (Arom-CH), 129.5 (Arom-CH), 126.9 (Arom-CH),
89.5 (C±O), 89.3 (C±O), 62.9 (OCH2), 53.9 (CH), 52.6
(CH), 47.6 (CH), 42.1 (CH2), 34.6 (CH), 33.0 (CH2), 29.7
(CH2), 25.6 (CH2), 16.0 (CH3), 14.9 (CH2), 14.2 (CH3).
6-Methyl-7,10,12-trioxo-11-phenyl-14-oxa-11-azatetra-
cyclo[6.5.1.01,6.09,13]tetradecane (15e). A mixture of N-
phenyl maleimide (105 mg, 0.6 mmol) and 1.3 mg of
Rh2(OAc)4 in dichloromethane (7 ml) was allowed to
react with a dichloromethane solution (3 ml) of diazo ketone
6d (55 mg, 0.3 mmol) at room temperature for 3 h accord-
ing to the general method A to afford 88 mg (88%) of 15e as
a white solid, mp 170±1728C (ethyl acetate/hexane);
[Found: C, 70.26; H, 5.83; N, 4.24. C19H19NO4 requires C,
70.14; H, 5.89; N, 4.30%]; nmax (KBr) 2934, 2864, 1768,
1709, 1595, 1498, 1385, 1199, 1160, 992 cm21; dH
(200 MHz, CDCl3) 7.51±7.42 (3H, m, Arom-H), 7.28±
7.23 (2H, m, Arom-H), 4.89 (1H, s, OCH), 3.21 (2H, s,
CH), 2.07±1.87 (2H, m), 1.80±1.59 (3H, m), 1.49±1.16
(3H, m), 1.09 (3H, s, tert-CH3); dC (50 MHz, CDCl3)
213.4 (CvO), 174.1 (NCO), 131.6 (quat-C), 129.2
(Arom-CH), 128.9 (Arom-CH), 126.4 (Arom-CH), 90.7
(C±O), 82.4 (OCH), 49.6 (CCH3), 47.9 (CH), 47.0 (CH),
30.4 (CH2), 25.7 (CH2), 21.9 (CH2), 19.9 (CH2), 16.2 (CH3).
2,7-Dimethyl-8,11,13-trioxo-12-phenyl-15-oxa-12-aza-
tetracyclo[7.5.1.01,6.010,14]pentadecane-9-carboxylic acid
ethyl ester (15c). A mixture of N-phenyl maleimide
(280 mg, 1.6 mmol) and 3.5 mg of Rh2(OAc)4 in dry ben-
zene (7 ml) was allowed to react with a benzene solution
(3 ml) of diazo ketone 14c (225 mg, 0.8 mmol) for 11 h at
re¯ux according to the general method B to afford 287 mg
(84%) of 15c as a white solid, mp 203±2048C (ethyl acetate/
hexane); [Found: C, 67.67; H, 6.32; N, 3.26. C24H27NO6
requires C, 67.75; H, 6.40; N, 3.29%]; nmax (KBr) 2933,
1775, 1742, 1716, 1652, 1393, 1319, 1218, 1028 cm21; dH
(200 MHz, CDCl3) 7.48±7.38 (3H, m, Arom-H), 7.29±7.23
(2H, m, Arom-H), 4.28 (2H, q, J7.2 Hz, OCH2), 3.89 (1H,
d, J8.3 Hz), 3.59 (1H, d, J8.3 Hz), 2.92±2.87 (1H, m),
2.38±2.09 (4H, m), 1.81±1.34 (4H, m), 1.37 (3H, t, J
7.2 Hz, CH2CH3), 1.23 (3H, d, J6.3 Hz), 0.95 (3H, d,
J6.2 Hz, CH3); dC (50 MHz, CDCl3) 198.3 (CvO),
176.1 (NCO), 173.0 (NCO), 168.2 (COO), 132.1 (quat-C),
130.2 (Arom-CH), 129.5 (Arom-CH), 127.2 (Arom-CH),
89.9 (C±O), 89.7 (C±O), 62.7 (OCH2), 53.8 (CH), 52.9
(CH), 48.2 (CH), 40.2 (CH), 35.3 (CH), 32.8 (CH2), 29.3
(CH2), 25.9 (CH2), 17.2 (CH3), 14.6 (CH3), 14.2 (CH3).
6-Methyl-7,10,12-trioxo-11-phenyl-14-oxa-11-azatetra-
cyclo[6.5.1.01,6.09,13]tetradecane-8-carboxylic acid ethyl
ester (15f). A mixture of N-phenyl maleimide (142 mg,
0.8 mmol) and 1.8 mg of Rh2(OAc)4 in benzene (7 ml)
was allowed to react with a benzene solution (3 ml) of
diazo ketone 6b (103 mg, 0.4 mmol) for 8 h at re¯ux
according to the general method B to afford 150 mg
(95%) of 15f as a white solid, mp 215±2178C (ethyl acetate/
hexane); [Found: C, 66.05; H, 5.81; N, 3.47. C22H23NO6
requires C, 66.49; H, 5.83; N, 3.52%]; nmax (KBr) 2933,
1774, 1741, 1715, 1393, 1317, 1212, 1074 cm21; dH
(200 MHz, CDCl3) 7.49±7.39 (3H, m, Arom-H), 7.26±
7.22 (2H, m, Arom-H), 4.40 (2H, q, J7.2 Hz, OCH2),
3.51 (1H, d, J8.0 Hz), 3.29 (1H, d, J8.0 Hz), 2.09±
1.67 (6H, m), 1.38 (3H, t, J7.2 Hz, CH2CH3), 1.46±1.34
(2H, m), 1.23 (3H, s, tert-CH3); dC (50 MHz, CDCl3) 207.6
(CvO), 173.5 (NCO), 172.4 (NCO), 163.3 (COO), 132.1
(quat-C), 129.7 (Arom-CH), 129.5 (Arom-CH), 127.0
(Arom-CH), 90.1 (C±O), 89.7 (C±O), 62.9 (OCH2), 50.4
(quat-C), 49.7 (CH), 49.1 (CH), 31.3 (CH2), 26.1 (CH2),
22.2 (CH2), 20.3 (CH2), 16.9 (CH3), 14.7 (CH3); m/z 397
(M1, 48), 351 (43), 305 (100), 204 (44), 175 (30), 149 (54),
115 (21), 98 (25%).
2,9-Dimethyl-8,11,13-trioxo-12-phenyl-15-oxa-12-aza-
tetracyclo[7.5.1.01,6.010,14]pentadecane (15d). A mixture
of N-phenyl maleimide (375 mg, 2.2 mmol) and 4.8 mg of
Rh2(OAc)4 in dichloromethane (15 ml) was allowed to react
with a dichloromethane solution (5 ml) of diazo ketone 14d
(225 mg, 1.1 mmol) at room temperature for 9 h according
to the general method A to afford 263 mg (69%) of 15d as a
white solid, mp 182±1838C (ethyl acetate/hexane); [Found:
C, 71.46; H, 6.43; N, 3.84. C21H23NO4 requires C, 71.37; H,
6.56; N, 3.96%]; nmax (KBr) 2938, 2863, 1768, 1707, 1598,
1493, 1386, 1237, 1120, 990 cm21; dH (200 MHz, CDCl3)
7.52±7.40 (3H, m, Arom-H), 7.28±7.24 (2H, m, Arom-H),
3.52 (1H, d, J8.0 Hz), 3.37 (1H, d, J8.0 Hz), 2.92 (1H,
dd, J114.2 Hz, J27.8 Hz), 2.40±2.01 (5H, m), 1.79±1.31
(4H, m), 1.51 (3H, s, CH3), 0.97 (3H, d, J6.4 Hz, CH3);
dC (50 MHz, CDCl3) 199.1 (CvO), 175.2 (NCO), 172.9
(NCO), 132.0 (quat-C), 129.9 (Arom-CH), 129.3
(Arom-CH), 126.6 (Arom-CH), 89.4 (C±O), 86.2 (C±O),
53.8 (CH), 52.3 (CH), 47.2 (CH), 42.2 (CH2), 34.7
(CH), 32.9 (CH2), 29.2 (CH2), 25.6 (CH2), 23.2 (CH3),
16.8 (CH3).
6,9-Dimethyl-7-oxo-11-oxatricyclo(6,2,1,01,6)undecane-
9-carboxylic acid 9-methyl ester (17a,b). A mixture of
methyl methacrylate (122 mg, 1.2 mmol) and 2.7 mg of
Rh2(OAc)4 in dichloromethane (7 ml) was allowed to
react with a dichloromethane solution (3 ml) of diazo ketone
6d (110 mg, 0.6 mmol) for 4 h according to the general
method A afforded the diasteromers 17a (16 mg, 10%)
and 17b (83 mg, 53%) as a thick liquid. 17a: [Found: C,
66.60; H, 7.82. C14H20O4 requires C, 66.65; H, 7.99%]; nmax
(neat) 2938, 2867, 1746, 1741, 1452, 1377, 1277, 1208,
1164, 1119, 998 cm21; dH (200 MHz, CDCl3) 4.12 (1H, s,
H-8), 3.68 (3H, s, OCH3), 2.70 (1H, d, J13.2 Hz), 1.93±
1.67 (6H, m), 1.63±1.26 (3H, m), 1.25 (3H, s, CH3), 1.09
(3H, s, CH3); dC (50 MHz, CDCl3) 216.8 (CvO), 176.5
(COO), 89.3 (C-1), 87.2 (C-8), 53.5 (OCH3), 51.5 (quat-
C), 50.3 (quat-C), 43.0 (CH2), 32.0 (CH2), 29.3 (CH2),
22.8 (CH2), 21.0 (CH2), 20.6 (CH3), 16.6 (CH3); 17b:
[Found: C, 66.59; H, 7.94. C14H20O4 requires C, 66.65; H,
7.99%]; nmax (neat) 2937, 2867, 1743, 1741, 1453, 1378,