532439-95-5Relevant articles and documents
Synthesis of γ-lactols, γ-lactones and 1,4-monoprotected succinaldehydes under moderately concentrated sunlight
Dondi, Daniele,Protti, Stefano,Albini, Angelo,Carpio, Sonia Manas,Fagnoni, Maurizio
, p. 1653 - 1659 (2009)
The usefulness of solar light for carrying out photocatalytic reactions involving the formation of a carbon-carbon bond has been explored. Thus, some radical alkylations of α,β-unsaturated acids or aldehydes have been carried out in a mixed aqueous solution. Under these conditions, alkyl radicals are generated from i-PrOH and 1,3-dioxolane by photocatalyzed hydrogen abstraction. A water soluble photocatalyst (disodium benzophenondisulfonate, BPSS) was used, which greatly simplifies work up. With reasonably efficient radical traps (e.g. maleic acid), the syntheses could be carried out up to completion on a 10 gram scale within 10-15 hours exposure to sunlight in a solar concentrator (SOLFIN apparatus) in November in Almeria (Spain). The alkylation of some α,β-unsaturated aldehydes have been likewise performed under the same conditions. The Royal Society of Chemistry 2009.
A convenient route to 1,4-monoprotected dialdehydes, 1,4-ketoaldehydes, γ-lactols and γ-lactones through radical alkylation of α,β-unsaturated aldehydes in organic and organic-aqueous media
Dondi, Daniele,Caprioli, Ilaria,Fagnoni, Maurizio,Mella, Mariella,Albini, Angelo
, p. 947 - 957 (2007/10/03)
α,β-Unsaturated aldehydes were smoothly alkylated by radicals generated through photosensitised hydrogen abstraction of benzophenone. In this way, and by using 1,3-dioxolane as radical precursor, monoprotected 1,4-dialdehydes were obtained from crotonaldehyde, 2-hexenal, 4-methyl-2-pentenal and cyclohexencarboxyaldehyde in a moderate yield, and in a low yield from β-aryl-α,β-unsaturated aldehydes. With 2-alkyl-1,3-dioxolanes, monoprotected 1,4-ketoaldehydes were analogously prepared. By using methanol, ethanol and isopropanol as radical precursors γ-lactols were likewise obtained from the above aliphatic aldehydes. These single-step syntheses compared favorably with multi-step approaches previously proposed for some of these compounds. The lactols were conveniently oxidized to the corresponding γ-lactones. An alternative to the photosensitisation in organic medium was the use of mixed aqueous-organic solvent and a hydrosoluble photosensitiser (benzophenone disodium disulfonate was prepared for this purpose and successfully used), which allowed a more convenient work up.
