Samarium(II) Iodide Mediated Conjugate Additions
J . Org. Chem., Vol. 62, No. 21, 1997 7427
0.81-1.01 (m, 2H); 13C NMR (100 MHz, CDCl
distillation (ot 100-120 °C, 10 mmHg): 1H NMR (500 MHz,
) δ 176.56, 59.91,
45.48, 40.74, 31.14, 29.60, 26.33, 26.28, 26.24, 14.29, 13.99;
3
CDCl ) δ 4.10 (q, J ) 7.15 Hz, 2H), 2.42 (dd, J ) 14.69, 4.96
3
-
1
Hz, 1H), 2.10 (dd, J ) 14.69, 9.13 Hz, 1H), 1.86-1.78 (m, 3H),
11
IR (neat) 1732.1 cm ; HRMS calcd for C H20O2 184.1463,
+
1
3
.56-1.48 (m, 3H), 1.31-1.28 (m, 1H), 1.23 (t, J ) 7.15 Hz,
found 184.1476; LRMS (EI ) m/ z 184 (21), 139 (99), 102 (100),
H), 1.21-1.10 (m, 3H), 0.87 (t, J ) 7.44 Hz, 3H); 13C NMR
111 (39), 74 (77), 69 (51), 55 (60), 41 (58), 29 (49). Anal. Calcd
(125 MHz, CDCl
3
) δ 173.57, 60.06, 47.38, 42.01, 39.82, 32.38,
for C11
20 2
H O : C, 72.70; H, 10.94; Found: C, 72.48; H, 11.16.
-1
3
1.48, 27.29, 23.52, 14.26, 12.65; IR (neat) 1731.8 cm ; HRMS
Eth yl (1R*,2S*)-2-n -P en tylcyclop en ta n ea ceta te (22a ).
2a was prepared from ethyl (2E)-7-iodo-2-dodecenoate, 21a ,
+
calcd for C11
1
5
H
20
O
2
: 184.1463, found 184.1460; LRMS (EI ) m/ z
84 (21), 139 (100), 109 (43), 96 (39), 88 (98), 67 (41), 61 (32),
5 (47), 41 (41).
2
according to the general procedure for the preparation of 10a
in 82% yield as a 4.3:1 mixture of diastereomeric products
N-Meth yl-2-(2-P r op en yl)cyclop en ta n ea ceta m id e (11d ).
1d was prepared from N-methoxy-N-methyl-(2E)-7-iodo-4-(2-
(
capillary GC) after flash column chromatography with 2%
1
1
EtOAc/hexanes: H NMR (400 MHz, CDCl
3
) δ 4.58 (m, 2H),
.78 (m, 2H), 2.53 (m, 1H), 2.31 (m, 1H), 2.22-1.92 (m, 4H),
.83-1.63 (m, 9H), 1.73 (m, 3H), 1.56 (m, 1H), 1.34 (m, 3H);
) δ 173.98,
60.07, 42.44, 38.96, 34.87, 32.15, 30.74, 29.95, 29.91, 28.17,
propenyl)-2-heptenamide, 9d , according to the general proce-
dure outlined for the preparation of 10a (except 5 equiv of SmI
were employed) in 78% yield as a 30:1 mixture of diastereo-
2
1
(
2
major diastereomer) 13C NMR (100 MHz, CDCl
3
mers after flash column chromatography with 70% EtOAc/
1
hexanes: H NMR (500 MHz, CDCl
3
) δ 5.81 (m, 1H), 5.44 (m,
-1
2
(
2.64, 22.35, 14.26, 14.07; IR (neat) 1738.0, 1465.6 cm ; LRMS
1
4
1
1
2
H), 5.02 (m, 2H), 2.83 (d, J ) 4.86 Hz, 3H), 2.40 (dd, J )
+
EI ) m/ z 226 (42), 197 (13), 181 (100), 155 (37), 138 (24), 127
.56, 13.80 Hz, 1H), 2.26 (m, 1H), 2.02-1.81 (m, 5H), 1.63-
.50 (m, 5H), 1.27 (m, 3H); 1 C NMR (125 MHz, CDCl
3
(13), 88 (98), 81 (32), 67 (41), 55 (43), 41 (45), 25 (42). Anal.
3
): δ
Calcd for C14
11.67.
26 2
H O : C, 74.29; H, 11.58. Found: C, 74.50; H,
73.28, 137.76, 115.25, 45.16, 42.25, 42.03, 38.86, 32.38, 31.55,
6.19, 23.45; IR (neat) 3465.5, 1664.1, 1522.0 cm ; HRMS
-
1
+
calcd for C11
81 (42), 140 (100), 123 (30), 73 (98), 58 (30), 40 (22). Anal.
Calcd for C11 22NO: C, 72.88; H, 10.56. Found: C, 72.68; H,
0.86.
Eth yl (1R*,2S*)-2-Meth ylcycloh exa n ea ceta te (13). 13
H
22NO 181.1467, found 181.1457; LRMS (EI ) m/ z
Eth yl (1R*,2S*,2′R*/S*)-2-(2′-n -P en tylcyclop en tyl)p r o-
p ion a te (22b). Prepared from ethyl (2E)-7-iodo-2-methyl-2-
dodecenoate, 21b, according to the general procedure for the
preparation of 10a to afford the desired cyclized product in
1
H
1
9
5% yield as a 10:2.8:1 mixture of diastereomers (capillary GC)
was prepared from ethyl (2Z)-8-iodo-4-methyl-2-octenoate, 12,
after flash column chromatography with 2% EtOAc/hexanes:
according to the general procedure outlined for the preparation
1
H NMR (400 MHz, CDCl
m, 2H), 1.75-1.48 (m, 5H), 1.36-1.05 (m, 8H), 1.23 (t, J )
3
) δ 4.09 (m, 2H), 2.32 (m, 1H), 1.88
1
of 10a as a single diastereomer ( H NMR) in 85% yield after
(
7
(
2
1
Kugelrohr distillation (ot 110-120 °C, 15 mmHg); H NMR
13
.23 Hz, 3H), 1.13 (d, J ) 6.69 Hz, 3H), 0.86 (m, 4H); C NMR
100 MHz, CDCl ) δ 177.21, 59.96, 47.74, 40.92, 39.55, 32.12,
9.32, 27.72, 27.61, 26.63, 22.71, 21.85, 16.66, 14.26, 14.08;
(
3
400 MHz, CDCl ) δ 4.10 (q, J ) 6.96 Hz, 2H), 2.50 (dd, J )
3
1
1
2
(
3
4.46, 4.28 Hz, 1H), 1.98 (dd, J ) 14.72, 9.10 Hz, 1H), 1.71-
.62 (m, 4H), 1.41 (m, 1H), 1.23 (t, J ) 7.23 Hz, 3H), 1.96 (m,
-1
+
IR (neat) 1735.7, 1460.3 cm ; LRMS (EI ) m/ z 240 (99), 225
H), 1.16-0.92 (m, 3H), 0.87 (d, J ) 6.42 Hz, 3H); 13C NMR
(
(
1
100), 197 (89), 167 (41), 102 (96), 95 (32), 83 (30), 69 (36), 55
25), 41 (13), 28 (14). Anal. Calcd for C15 : C, 74.95; H,
1.74. Found: C, 74.90; H, 11.89.
Eth yl 2-Meth ylcycloh exan eacetate (22c). Prepared from
100 MHz, CDCl
2.58, 26.37, 26.28, 20.17, 14.26; IR (neat) 1738.0 cm ; HRMS
3
) δ 173.74, 60.05, 41.35, 39.63, 37.23, 35.55,
28 2
H O
-1
+
calcd for C11
H
20
O
2
184.1455, found 184.1463; LRMS (EI ) m/ z
1
5
84 (20), 139 (100), 96 (20), 88 (99), 81 (12), 70 (21), 61 (40),
5 (39), 41 (29), 29 (30).
ethyl (2E)-8-iodo-2-nonenoate, 21c, according to the general
procedure outlined for the preparation of 10a to afford the
Eth yl 2-Cyclop en tylp r op ion a te (16a ). 16a was prepared
desired cyclized product as a 1:1 mixture of diastereomers
from 15a according to the general cyclization procedure
outlined for the preparation of 10a in 91% yield after flash
1
(
capillary GC and H NMR) in 77% combined yield after flash
1
column chromatography with 3% EtOAc/hexanes:
1
H NMR
column chromatography with 5% EtOAc/hexanes: H NMR
(
1
4
400 MHz, CDCl
3
) δ 4.10 (dq, J ) 1.87, 7.23 Hz, 2H), 2.21 (m,
H), 1.94 (m, 1H), 1.76 (m, 1H), 1.68 (m, 1H), 1.61-1.46 (m,
H), 1.23 (t, J ) 7.23 Hz, 3H), 1.18 (m, 2H), 1.12 (t, J ) 6.96
(400 MHz, CDCl ) δ 4.09 (q, J ) 7.23 Hz, 2H), 2.50 (dd, J )
3
4.55, 14.72 Hz, 0.5H), 2.28-2.12 (m, 1.5H), 2.06 (m, 0.5H), 1.97
(dd, J ) 8.83, 14.72 Hz, 0.5H), 1.78 (m, 0.5H), 1.71-1.59 (m,
1H), 1.52 (m, 0.5H), 1.48-1.28 (m, 4H), 1.23 (t, J ) 7.23 Hz,
3H), 1.19 (m, 1H), 1.12-0.96 (m, 2H), 0.87 (d, J ) 6.43 Hz,
1
3
Hz, 3H); C NMR (100 MHz, CDCl
3
) δ 176.77, 59.94, 45.10,
4
1
1
3.48, 30.83, 30.27, 25.17, 25.08, 16.17, 14.28; IR (neat) 1731.9,
455.3, 1373.5 cm ; HRMS calcd for C10
70.1302; LRMS (EI ) m/ z 170 (11), 155 (99), 127 (76), 102
-1
13
H
18
O
2
170.1307, found
1.5H), 0.82 (d, J ) 6.43 Hz, 1.5H); C NMR (100 MHz, CDCl3)
+
δ 173.74, 60.06, 41.33, 39.62, 37.22, 36.99, 35.53, 32.56, 32.51,
(
100), 97 (34), 74 (50), 67 (21), 55 (83), 41 (70), 29 (99). Anal.
Calcd for C10 : C, 70.55; H, 10.66. Found: C, 70.98; H,
0.78.
E t h yl 2-[(1R*,2R*)-2-Met h ylcyclop en t yl]p r op ion a t e
16b). 16b was prepared from 15b according to the general
31.95, 27.97, 26.36, 26.26, 24.28, 22.19, 20.17, 14.72, 14.25;
H
18
O
2
IR (neat) 1737.9 cm-1; HRMS calcd for C H20O2 184.1463,
1
1
1
+
found 184.1477; LRMS (EI ) m/ z 184 (11), 139 (100), 97 (41),
8 (98), 81 (26), 70 (31), 61 (50), 55 (53), 41 (38), 29 (33). Anal.
Calcd for C11 : C, 71.70; H, 10.94. Found: C, 72.11; H,
1.09.
N-Met h yl-(1R*,2R*)-2-n -p en t yl-1-cyclop en t a n ea cet a -
m id e (22d ). 22d was prepared from N-methoxy-N-methyl-
2E)-7-iodo-2-dodecenamide, 21d , according to the general
procedure for the preparation of 10a (except 5 equiv of SmI
8
(
20 2
H O
cyclization procedure for 10a in 87% yield as a 5.3:1 mixture
1
of diastereomers epimeric at C-2 and isolated by flash column
1
chromatography with 5% EtOAc/hexanes: H NMR (400 MHz,
CDCl
3
) δ 4.09 (dq, J ) 7.23, 2.14 Hz, 2H), 2.40 (m, 1H), 1.79-
.63 (m, 3H), 1.59-1.48 (m, 3H), 1.34 (m, 1H), 1.23 (t, J )
.23 Hz, 3H), 1.19 (m, 1H), 1.13 (d, J ) 6.96 Hz, 3H), 0.97 (d,
(
1
7
2
1
3
were employed in this reaction) in 85% of yield as a 30:1
mixture of diastereomeric products (capillary GC) of undeter-
mined stereochemistry. The product was isolated using flash
J ) 6.43 Hz, 3H); C NMR (100 MHz, CDCl
0.23, 43.12, 37.21, 35.21, 30.28, 24.00, 20.93, 15.69, 14.29;
IR (neat) 1731.8, 1548.1, 1512.6, 1462.0, 1377.7, 1333.1,
3
) δ 176.28, 59.89,
5
1
-
1
column chromatography with 50% EtOAc/hexanes: H NMR
1
1
255.1, 1158.7 cm ; HRMS calcd for C11
H
20
O
2
184.1477, found
+
(400 MHz, CDCl
3
) δ 5.42 (s, 1H), 2.78 (d, J ) 4.88 Hz, 3H),
84.1463; LRMS (EI ) m/ z 184 (13), 169 (98), 139 (71), 111
2
1
1
.31 (m, 1H), 2.22 (dd, J ) 13.92, 5.13 Hz, 1H), 1.84 (dd, J )
(
(
46), 102 (100), 95 (21), 81 (25), 74 (72), 69 (53), 55 (81), 41
90).
0.50, 13.92 Hz, 1H), 1.83 (m, 1H), 1.76-1.42 (m, 4H), 1.36-
.02 (m, 10H), 0.86 (t, J ) 6.84 Hz, 3H); 13C NMR (100 MHz,
Eth yl 2-Meth ylcycloh exa n ea ceta te (16c). 16c was pre-
pared from ethyl (2E)-8-iodo-2-methyl-2-octenoate according
to the general procedure outlined for the preparation of 10a
CDCl
3
) δ 173.90, 42.47, 39.31, 36.79, 32.13, 30.51, 29.24 (2),
28.11, 26.09, 22.60, 22.32, 14.03; IR (neat) 3299.2, 1659.0,
-1
+
in 38% yield after flash column chromatography with 2%
1643.7, 1567.2, 1555.7, 1453.9 cm ; LRMS (EI ) m/ z 211 (34),
1
EtOAc/hexanes: H NMR (400 MHz, CDCl
6
3
) δ 4.10 (dq, J )
196 (8), 182 (32), 168 (100), 140 (54), 154 (43), 73 (50), 58 (42),
.69, 2.67 Hz, 2H), 2.20 (m, 1H), 1.72-1.39 (m, 6H), 1.23 (t, J
41 (30). Anal. Calcd for C13
Found: C, 73.61; H, 12.19.
H25NO: C, 73.88; H, 11.84.
)
6.96 Hz, 3H), 1.21-1.12 (m, 3H), 1.07 (d, J ) 6.96 Hz, 3H),