ISSN:
1434-193X
Keywords:
Cycloadditions
;
Cage compounds
;
Dimerizations
;
Steric hindrance
;
Photochemistry
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
---On irradiation at λ ≥ 270 nm solutions of 4-aryl-1,4-dihydropyridines 1 yield cage dimers 2 as the main products beside small amounts of anti dimers 3. 1H-NMR data and X-ray crystal structure prove centrosymmetrical properties for both dimers with axially orientated 4-aryl substituents. Irradiation with filtered light (λ 〉 313 nm) leads to syn and anti dimers 4 and 3 in nearly equal yields. The poor yields of anti dimers 3 on irradiation with unfiltered light are demonstrated to result from a partial cleavage back to their monomeric starting materials 1.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
Permalink