41264-06-6Relevant articles and documents
ReBr(CO)5-catalyzed sequential addition-cyclization of 1,3-dicarbonyl compounds with electron-deficient internal alkynes affording trisubstituted 2H-pyran-2-ones
Zhao, Wen-Guo,Hua, Ruimao
, p. 11803 - 11808 (2007)
The reaction of 1,3-dicarbonyl compounds such as acetoacetate, acetylacetone, dibenzoylmethane, and benzoylacetate with electron-deficient internal alkynes in the presence of catalytic amount of ReBr(CO)5 in toluene under neutral conditions resulted in the formation of 4,5,6-trisubstituted 2H-pyran-2-ones in moderate to high yield. The reaction took place via a two-step sequence including the rhenium(I)-catalyzed addition of the activated methylenes to alkynes to give enolic 2-alkenyl derivatives, and subsequently dealcoholic cyclization to form 2H-pyran-2-one derivatives.
Studies on Metabolites of Macrophoma commelinae. IV. Substrate Specificity in the Biotransformation of 2-Pyrones to Substituted Benzoic Acids
Sakurai, Ikuo,Miyajima, Hisae,Akiyama, Katsuyoshi,Shimizu, Sakae,Yamamoto, Yuzuru
, p. 2003 - 2011 (2007/10/02)
Substrate specificity in the novel biotransformation from 2-pyrone derivatives to substituted benzoic acids by Macrophoma commelinae (IFO 9570) was investigated by means of feeding experiments with various compounds.Among them, 2-pyrone derivatives substituted by an electron-donating group at C-4, by an electron-withdrawing group at C-5 and by an alkyl group at C-6 were converted to the corresponding benzoic acid derivatives in fairly good yields.The C3-unit precursors and intermediates were examined in stationary or shaking culture.Based on the experimental results obtained, a mechanism for this unique reaction is proposed. macrophoma commelinae IFO 9570; fungi; 2-pyrone; substituted benzoic acid; biotransformation; substrate specificity; aromatic ring formation; macrophomic acid
