7752
U. Sudhir et al. / Tetrahedron 57 ꢀ2001) 7749±7753
chromatography was carried out using silica gel %100±200
mesh). Mixtures of ethyl acetate and hexane and pure ethyl
acetate were used as eluent as required. Melting points were
recorded on Aldrich Meltemp-II and are reported without
corrections. IR spectra were run on a Nicolet %impact 400D
FT-IR) spectrophotometer or Bomem MB-Series FT-IR
spectrophotometer. NMR spectra were obtained using
chloroform-d as solvent on Bruker DPX 300 MHz NMR
spectrometer. Chemical shifts are given in d scale with
TMS as internal reference. Yields refer to quantities
obtained after chromatography.
heating an aqueous solution of the amine in a water bath)
was passed through this solution for 0.5 h and then the reac-
tion mixture was allowed to come to room temperature and
stirred for 0.5 h more. After this, the reaction was worked up
by removing the solvent under reduced pressure on the rota-
vapor. The crude product mixture was loaded on a silica gel
column and then successively eluted with 50, 80 and 90%
ethyl acetate in petroleum ether followed by elution with
pure ethyl acetate. The pure fractions were pooled together
and crystallised from dichloromethane±petroleum ether
mixture.
3.3.1. Spectral data for 4-azamethyl-6-bromomethyl-5-
hydroxypentacyclo[5.4.1.02,6.05,9.08,11]dodec-10113)-ene-
3-one, 3a. Colourless crystalline solid, mp %8C): 200±202.
FT-IR %KBr, nmax/cm21): 3137, 2962, 2948, 1654, 1431,
3.1. Procedure for the Diels±Alder reaction of 8
The quinone 8 %0.64 g, 3.2 mmol) was dissolved in dry
benzene and the solution was cooled in an ice-water bath.
Cyclopentadiene %0.60 mL, 7.3 mmol) was added slowly to
this solution drop by drop. The reaction mixture was left
stirring at room temperature for 20 h. It was worked up by
removing benzene under reduced pressure and then puri®ed
on a silica-gel column. The compound was recrystallised
from dichloromethane±petroleum ether and gave light
yellow coloured crystals %0.74 g, 87% yield) of the Diels±
Alder adduct 2,5-bis%chloromethyl)tricyclo[6.2.1.02,7]-
undec-4,9-diene-3,6-dione, 9.
1
1378, 1283, 1263, 1243, 1155, 1088, 1027, 899, 791. H
NMR %300 MHz, CDCl3): d 4.87 %s, 1H), 4.79 %s, 1H),
3.79 %brs, 1H), 3.58 %s, 2H), 3.35 %brs, 1H), 3.07 %brs, 1H),
3.00±2.96 %m, 1H), 2.82±2.77 %m, 2H), 2.63 %s, 3H), 2.56 %d,
J4.9 Hz, 1H), 2.02 %d, J10.4 Hz, 1H), 1.58 %d,
J10.5 Hz, 1H). 13C NMR %75 MHz, CDCl3): d 171.2,
143.6, 108.9, 101.9, 63.1, 60.2, 55.9, 51.1, 49.5, 45.1,
44.4, 42.8, 34.7, 24.6. HRMS %M111): 310.0437,
C14H16NO2Br requires 309.0364. Crystal data for 3a:
CCDC No. 163822. C14H16BrNO2, colourless crystalline
solid, 0.30£0.24£0.20 mm3, orthorhombic, space group:
3.1.1. Spectral data of 9. Mp %8C): 118±120. FT-IR %KBr,
n
max/cm21): 3020, 2982, 1670, 1625, 1432, 1073, 708. H
P212121. Unit cell dimensions: a6.4973%1) A, a908;
1
Ê
Ê
Ê
NMR %300 MHz, CDCl3): d 6.82 %s, 1H), 6.12 %s, 2H),
4.38±4.19 %m, 3H), 3.50±3.42 %m, 2H), 3.25±3.23 %m,
1H), 3.12 %s, 1H), 1.64 %s, 2H). 13C NMR %75 MHz,
CDCl3): d 199.3, 196.8, 148.6, 140.1, 136.9, 136.4, 60.1,
55.0, 53.1, 51.8, 49.8, 47.2, 39.6.
b12.8707%2) A, b908; c15.6425%3) A, g908. R
indices %all data): R10.0420, wR20.0857. Volume
Ê 3
23
1308.10%4) A , Z4. Density %calculated)1.575 mg m
.
F%000)632. Absorption coef®cient3.136 mm21
.
3.3.2. Spectral data for 7-bromomethyl-8-1N-methyl-
carbomoyl)tetracyclo[4.2.1.14,7.02,5]dec-3111)-ene-10-
one, 5a. Mp %8C): 129±131. FT-IR %KBr, nmax/cm21): 2965,
3.2. Procedure for photolysis of 9
1
2865, 1738, 1651, 1538, 1370, 1240, 1109, 885. H NMR
The Diels±Alder adduct 9 %0.74 g, 2.7 mmol) was dissolved
in 80 mL of dry ethyl acetate, degassed with argon gas and
exposed to bright sunlight for 2 h. TLC at the end of this
period showed complete consumption of the UV active
starting material along with the formation a non-UV active
product. The reaction was worked up by removing the
solvent and the residue was puri®ed by column chromato-
graphy on silica gel. The pure product was crystallised from
a mixture of dichloromethane and petroleum ether to give
off-white crystals of 2 %0.61 g, 83% yield).
%300 MHz, CDCl31CCl4): d 5.26 %brs, 1H), 5.03 %s, 1H),
4.86 %s, 1H), 3.74 %d, J10.4 Hz, 1H), 3.40 %d, J10.4 Hz,
1H), 3.15±3.11 %m, 3H), 2.93±2.89 %m, 3H), 2.53 %d,
J4.6 Hz, 3H), 1.63 %d, J10.4 Hz, 1H), 1.52 %d,
J10.4 Hz, 1H). 13C NMR %75 MHz, CDCl31CCl4): d
214.5, 170.7, 146.6, 111.6, 58.8, 56.8, 46.2, 45.8, 44.5,
41.9, 39.6, 38.3, 33.8, 26.1. HRMS %M111): 310.0386,
C14H16BrNO2 requires 309.0364.
3.3.3. Spectral data for 3b. Mp %8C): 231±233. FT-IR
%KBr, nmax/cm21): 3349, 3074, 2980, 2874, 1651, 1539,
1414, 1345, 1270, 1133, 1095, 877. H NMR %300 MHz,
3.2.1. Spectral data of 2. Mp %8C): 88±90. FT-IR %KBr,
n
max/cm21): 2970, 1757, 1738, 1430, 1284, 1146, 1100,
1
1
732. H NMR %300 MHz, CDCl3): d 3.77±3.51 %m, 4H),
3.23±3.17 %m, 2H), 3.03±2.99 %m, 2H), 2.82±2.79 %m,
1H), 2.62 %d, J3.4 Hz, 1H), 2.27 %d, J11.7 Hz, 1H),
1.95 %d, J11.7 Hz, 1H). 13C NMR %75 MHz, CDCl3): d
208.9, 208.1, 62.8, 58.9, 52.6, 46.9, 46.2, 43.7, 41.9, 41.7,
41.5, 39.3, 34.9. C/H Analysis: calculated for C13H12O2Cl2
C: 57.58, H: 4.46; found C: 57.74, H: 4.45.
CDCl3): d 5.94 %brs, 1H), 5.03 %s, 1H), 4.92 %s, 1H), 3.75
%d, J11.1 Hz, 1H), 3.69 %d, J11.1 Hz, 1H), 3.39±3.32 %m,
3H), 3.09 %s, 1H), 3.04±2.97 %m, 3H), 2.79 %d, J5.3 Hz,
1H), 2.15 %d, J10.7 Hz, 1H), 1.55 %d, J10.6 Hz, 1H),
1.25±1.12 %m, 3H). 13C NMR %75 MHz, CDCl3): d 176.6,
139.6, 113.8, 104.8, 55.7, 54.7 %2C), 50.2, 50.0, 47.3, 42.2,
40.6, 38.1, 36.3, 16.3. HRMS %M1): 323.0519,
C15H18NO2Br requires 323.0521.
3.3. General procedure for the reaction of the penta-
cyclic compounds with methylamine or ethylamine
3.3.4. Spectral data for 5b. Mp %8C): 159±161. FT-IR
%KBr, nmax/cm21): 3093, 2980, 2868, 1732, 1695, 1414,
1276, 1251, 1139, 883. H NMR %300 MHz, CDCl3): d
5.23 %brs, 1H), 4.91 %s, 1H), 4.83 %s, 1H), 3.73 %d,
J10.7 Hz, 1H), 3.56 %d, J10.7 Hz, 1H), 3.31 %brs, 1H),
1
The compound 1 or 2 %,100 mg) was taken in 10 mL of dry
benzene and the solution was cooled in an ice-water bath
%5±108C). Methylamine gas or ethylamine gas %produced by