dC 166.98 (quat), 162.98, 143.52, 99.22, 51.29 and 27.47; m/z 143
and 15.45; m/z 167 (M+, 8%), 139 (67), 111 (68), 96 (65), 86 (56),
85 (47), 84 (100), 83 (84), 82 (52) and 68 (75).
(M+, 26%), 125 (37), 115 (56), 112 (41) and 84 (100).
Methyl 3-[N-(2-oxopyrrolidin-1-yl)]prop-2-enoate 19
7-Hydroxy-1,2-dihydropyrrolizin-3(2H)-one 31
(Pyrrolidin-2-one, 72 h, chromatography) gave methyl◦3-[N-(2-
oxopyrrolidin-1-yl)]prop-2-enoate 19 (19%), mp 83–84 C (from
hexane/toluene), (Found: C, 56.95; H, 6.85; N, 8.15. C8H11NO3
requires C, 56.8; H, 6.55; N, 8.3%); dH 8.01 (1H, d, 3J 14.3), 5.13
(1H, d, J 14.3), 3.65 (3H, s), 3.49 (2H, t, J 7.2), 2.47 (2H, t, J
7.8) and 2.15–2.05 (2H, m); dC 174.02 (quat), 167.34 (quat), 137.14,
99.85, 51.08, 44.65, 30.62 and 17.10; (NMR data consistent with
published spectra27) m/z 169 (M+, 100%), 138 (37), 137 (13), 114
(8), 110 (42), 82 (49) and 70 (17).
FVP of 2,2-dimethyl-5-[N-(2-oxopyrrolidin-1-yl)methylene]-1,3-
dioxane-4,6-dione 9 [1.79 g (7.5 mmol) Tf 700 ◦C, Ti 170 ◦C, P
0.02 Torr, t 150 min] produced 7-hydroxy-1,2-dihydropyrrolizin-
3(2H)-one 31 which was purified by recrystallisation, (62%), mp
149–150 ◦C (dec.) (from ethyl acetate/methanol), (Found: C, 61.1;
H, 5.1; N, 9.95. C7H7NO2 requires C, 61.3; H, 5.15; N, 10.2%);
3
3
3
3
dH ([2H6]DMSO) 8.57 (1H, s), 6.79 (1H, d, J 3.1), 6.09 (1H, d,
3J 3.1), and 2.95–2.75 (4H, m); dC ([2H6]DMSO) 171.71 (quat),
137.89 (quat), 118.28 (quat), 113.01, 108.09, 34.43 and 17.83; m/z
137 (M+, 98%), 109 (16), 108 (19), 96 (20), 95 (100), 81 (17), 80
(38), 68 (15) and 67 (29).
Methyl 3-[N-(5-methyl-2-oxopyrrolidin-1-yl)]prop-2-enoate 22
(5-Methylpyrrolidin-2-one, 138 h, chromatography) gave methyl
3-[N◦-(5-methyl-2-oxopyrrolidin-1-yl)]prop-2-enoate 22 (26%), bp
105 C (0.7 Torr), (Found: M+, 183.0907. C9H13NO3 requires M,
183.0895); dH 7.93 (1H, d, 3J 14.5), 5.21 (1H, d, 3J 14.5), 4.00 (1H,
m), 3.66 (3H, s), 2.63–2.16 (3H, m), 1.74 (1H, m) and 1.21 (3H,
7a-Methyl-7,7a-dihydro-6H-pyrrolizine-1,5-dione 32
FVP of 2,2-dimethyl-5-[N-(5-methyl-2-oxopyrrolidin-1-yl)me-
thylene]-1,3-dioxane-4,6-dione 10 [1.91 g (7.2 mmol), Tf 700 C,
◦
Ti 180 ◦C, P 0.01 Torr, t 90 min] gave 7a-methyl-7,7a-dihydro-
6H-pyrrolizine-1,5-dione 32 (0.74 g, 68%), which was purified by
Kugelrohr distillation [bp 145 ◦C (0.2 Torr)], mp 91–92 ◦C. (Found:
C, 63.35; H, 5.95; N, 9.1. C8H9NO2 requires C, 63.55; H, 6.0; N,
9.25%); dH 8.11 (1H, d, 3J 4.0), 5.56 (1H, d, 3J 4.0), 2.92 (1H, ddd,
2J 17.4, 3J 12.7 and 8.1), 2.53 (1H, dd, 2J 17.4 and 3J 7.7), 2.10–
1.88 (2H, m) and 1.41 (3H, s); dC 205.27 (quat), 172.45 (quat),
152.99, 111.64, 69.09 (quat), 34.40, 27.56 and 22.09; m/z 151 (M+,
100%), 123 (27), 122 (17), 95 (43), 82 (19), 81 (60), 80 (32), 68 (26)
and 67 (72).
3
d, J 6.4); dC 173.73 (quat), 167.51 (quat), 136.18, 99.85, 51.09,
52.23, 29.15, 25.60 and 17.63; m/z 183 (M+, 68%), 168 (42), 152
(69), 151 (27), 124 (95), 108 (17), 96 (100), 83 (20) and 70 (34).
All of these reactions consistently produced the same by-
product in small amounts (30–100 mg) which could be isolated
from the column, always eluting first. This was identified as
◦
trimethyl◦1,3,5-benzenetricarboxylate 28 mp 140–141 C (lit.,28
141–142 C); dH 8.81 (3H, s) and 3.94 (9H, s); dC 165.19 (quat),
134.37, 131.01 (quat) and 52.44; m/z 252 (M+, 10%), 222 (6), 221
(43), 193 (6), 44 (42) and 40 (100).
1-Hydroxypyrrolo[2,1-a]isoindol-5-one 33
FVP experiments
FVP of 2,2-dimethyl-5-[N-(1-oxo-2,3-dihydroisoindol-2-yl)me-
◦
The substrate was volatilised into the furnace tube (35 ¥ 2.5 cm)
and the products were collected in a U-tube trap cooled by
liquid nitrogen situated at the exit point of the furnace. Quantity
of substrate, furnace temperature (Tf), inlet temperature (Ti),
background pressure (P) and reaction time (t) are specified. After
pyrolysis, involatile solid products were scraped from the trap,
whereas volatile solids and liquids were washed from the trap with
solvent. After the solvent had been removed under reduced pres-
sure, the crude pyrolysate was purified by either recrystallisation,
Kugelrohr distillation or dry flash column chromatography (using
ethyl acetate and n-hexane as eluents).
thylene]-1,3-dioxane-4,6-dione 11 [0.80 g (2.8 mmol), Tf 700 C,
Ti 165 ◦C, P 0.01 Torr, t 180 min] produced 1-hydroxypyrrolo[2,1-
a]isoindol-5-one 33 which was purified by recrystallisation, (0.41 g,
80%), mp 100–101 ◦C (from chloroform/hexane). (Found: C, 71.1;
H, 4.1; N, 7.8. C11H7NO2 requires C, 71.35; H, 3.8; N, 7.55%); dH
([2H6]acetone) 9.02 (1H, br s), 7.60–7.39 (3H, m), 7.15 (1H, m),
3
3
6.95 (1H, d, J 3.4) and 5.95 (1H, d, J 3.4); dC ([2H6]acetone)
160.86 (quat), 142.39 (quat), 135.24 (quat), 133.46, 129.63 (quat),
124.34 (2CH), 118.35, 115.53, 114.50 (quat) and 110.17; m/z 185
(M+, 100%), 157 (18), 133 (24), 132 (13), 130 (10), 129 (12), 104
(12), 103 (18), 102 (12) and 76 (11).
FVP of 2,2-dimethyl-5-[N-(2-oxopiperidinyl)methylene]-1,3-
9b-Phenyl-9bH-pyrrolo[2,1-a]isoindole-1,5-dione 34
dioxane-4,6-dione 14
FVP of 5-(1H-2,3-dihydro-1-oxo-3-phenylisoindol-2-yl)methyl-
ene-2,2-dimethyl-1,3-dioxane-4,6-dione 12 [(0.5 g (1.4 mmol), Tf
600 ◦C, Ti 275 ◦C, P 0.01–0.1 Torr, t 4 h] gave 9b-phenyl-9bH-
pyrrolo[2,1-a]isoindole-1,5-dione 34 (0.24 g, 65%) which was pu-
rified by recrystallisation, mp 110–112 ◦C (from hexane/toluene)
(Found: C, 78.15; H, 4.2; N, 5.4. C17H11NO2 requires C, 78.1; H,
FVP of 14 [1.27 g (5.0 mmol), Tf 700 ◦C, Ti 195 ◦C, P 0.02
Torr, t 90 min] produced a complex mixture that was subjected
to dry flash chromatography using n-hexane and ethyl acetate as
eluents. The only identifiable product obtained was 8a-hydroxy-
7,8-dihydroindolizine-1,5(6H,8aH)-dione 30 (0.12 g, 14%), bp
◦
120 C (0.3 Torr), (Found: M+, 167.0588. C8H9NO3 requires M,
4.2; N, 5.4%); dH 8.44 (1H, d, J 4.0), 7.87–7.80 (2H, m), 7.79–
3
167.0582); dH 8.48 (1H, d, 3J 4.4), 5.57 (1H, d, 3J 4.4), 2.88 (1H,
m), 2.65–2.06 (3H, m), 1.86 (1H, m) and 1.42 (1H, m); dC 201.42
(quat), 168.17 (quat), 154.89, 106.80, 84.63 (quat), 29.88, 27.50
7.62 (3H, m), 7.48 (1H, td, 3J 7.6 and 4J 1.0), 7.38–7.17 (3H, m)
3
and 5.84 (1H, d, J 4.0); dC 197.27 (quat), 168.83 (quat), 157.32,
145.22 (quat), 137.22 (quat), 135.11, 130.61 (quat), 128.86, 128.66,
This journal is
The Royal Society of Chemistry 2009
Org. Biomol. Chem., 2009, 7, 4936–4942 | 4941
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