A novel synthesis of α-hydroxy- and α,α′-dihydroxyketone from α-iodo and α,α′-diiodo ketone using photoirradiation
摘要:
A novel reaction of alpha-iodo ketone (alpha-iodocycloalkanone, alpha-iodo-beta-alkoxy ester, and alpha-iodoacyclicketone) with irradiation under a high-pressure mercury lamp gave the corresponding alpha-hydroxyketone in good yields. In the case of alpha,alpha'-diiodo ketone, alpha,alpha'-dihydroxyketone which little has been reported until now was obtained. This reaction affords a new, clean and convenient synthetic method for alpha-hydroxy- and alpha,alpha'-dihydroxyketone. (C) 2003 Elsevier Ltd. All rights reserved.
Oxidation of α-iodo ketone in CH 2 Cl 2 using m-chloroperbenzoic acid yields α,β-unsaturatedketone by β-H elimination in good yield. This reaction affords a new and convenient synthetic method for α,β-unsaturatedketone from u-iodo ketone.
Irradiation of α-iodo ketone in hexane under a nitrogen atmosphere with a high-pressure mercury lamp (λ>300nm) at room temperature afforded the corresponding α,β-unsaturatedketones in good yield. This reaction affords a new, clean and convenient synthetic method for the α,β-unsaturatedketone.
A novel protocol for the synthesis of α-iodoketones from alcohols has been developed. Using water as the reaction medium, ammonium iodide and Oxone® was proven to be an efficient reagent system for this reaction and afforded the corresponding α-iodoketones in moderate to good yields. The generality of this reaction was demonstrated with various secondary alcohols such as benzylic alcohols and aliphatic
The reaction of g.-halo ketones (alpha-iodocycloalkanones, alpha-bromocycloalkanones, alpha-iodo-beta-alkoxy esters, and alpha-iodoacyclic-ketones) with irradiation under a high-pressure mercury lamp gave the corresponding alpha-hydroxyketones in good yields. For alpha-bromoketones, it was found that alpha-hydroxylation does not occur. However, alpha-bromoketones were convened into a-hydroxyketones in the presence of KI. In the case of alpha,alpha(1)-diiodo ketones, alpha,alpha(1)-dihydroxyketones, which up to now have scarcely been reported, were obtained. This reaction affords a new, clean and convenient synthetic method for alpha-hydroxy- and alpha,alpha(1)-dihydroxyketones. (C) 2005 Elsevier Ltd. All rights reserved.