Photochemical [2π + 2σ] Cycloadditions in Tetracyclo[3.3.2.02,4.06,8]decene Systems†‡
First published: November 1969
No abstract is available for this article.
- 1
Photochemical Transformations, Part 31. – Part 30:
G. Kaupp and
H. Prinzbach,
Helv. Chim. Acta
52, 956
(1969).
- 2
H. Prinzbach,
W. Eberbach, and
G. Philippossian,
Angew. Chem.
80, 910
(1968);
Angew. Chem. internat. Edit.
7, 887
(1968);
cf. also
R. S. Liu,
Tetrahedron Letters
1968, 4073;
S. F. Nelsen and
J. P. Gillespie,
Tetrahedron Letters
1969, 59.
- 3
Cu-catalyzed reaction of methyl diazoacetate with (2) (ratio ca. 1:2) at 125 °C, followed by distillation and recrystallization, gives (5a) in non-optimal yield of ca. 50%. With a nine-fold excess of 40% peracetic acid in CH2Cl2 at 40 °C for 11 h, (2) gives ca. 80% of (5b).
- 4Varying the oxygen content of the solution does not affect the rate or product of the reaction; preliminary findings indicate that sensitization by acetone or benzophenone does not lead to (6).
- 5
Total reaction is achieved in 4–5 hours' irradiation of a solution of (5a) (1 g) or (5b) (1.2 g) in CH3CN (280 ml) at −30 °C with Vycor-filtered light from a Hanau-Q 81 mercury high-pressure lamp. In the case of (5a), 1% of a second component (24) could be detected by gas chromatography alongside 99% of (6a).
- 6
For photochemical ethylene-oxirane cycloaddition see
H. Prinzbach and
M. Klaus,
Angew. Chem.
81, 389
(1969);
Angew. Chem. internat. Edit.
8, 276
(1969).
- 7(7) is obtained quantitatively when an ethereal solution of (5) is mixed with a ca. ten-fold excess of diazomethane and kept for ca. 14 days. Photolysis of (8) was effected with a Pyrex filter (Q 81) in tetrahydrofuran at −30 °C.
- 8
G. I. Fray,
R. J. Hilton, and
J. M. Teire,
J. chem. Soc. (London) C
1966, 592.
- 9He is the methylene proton in Ch–COOCH3.
- 10
A. A. Bothner-By in
J. S. Waugh:
Advances in Magnetic Resonance. Vol. I,
p. 195; Academic Press,
New York 1965.
- 11
H. Prinzbach,
W. Eberbach,
M. Klaus, and
G. v. Veh,
Chem. Ber.
101, 4066
(1968);
H. Prinzbach and
H. D. Martin,
Chimia
23, 37
(1969).
