245116-66-9Relevant academic research and scientific papers
Oligomers of Alternately Arranged Chalcone Building Blocks
Aust, Harald,Ickenroth, Dirk,Meier, Herbert
, p. 523 - 528 (2007/10/03)
The cross-conjugated oligomers 1a-d, which contain up to eight alternately arranged chalcone building blocks, were prepared by stereoselective condensation reactions of formyl and acetyl components. The synthetic sequence started with 1,4-dibromo-2,5-dipropoxybenzene (2). Bouveault reactions with DMF and DMA yielded the aldehydes 3 and 6 and the ketones 7 and 10. After the protection of the carbonyl group (3 → 4 and 7 → 8), a further Bouveault reaction led to monoprotected dialdehyd 5 and dike-tone 9, respectively. Repetitive condensation reactions starting with the acetophenone derivative 11 and 5 furnished the aldehyde 12, the ketone 13 and the aldehyde 14. In the final step the target compounds 1 were obtained again by condensation reactions: 6 + 11 → 1a, 10 + 12 → 1b, 6 + 13 → 1c, 10 + 14 → 1d. Thus a convergent and coupled synthesis was achieved in order to generate constitutionally and configurationally pure oligochalcones.
