139067-63-3Relevant articles and documents
Structure and Stereochemistry of Four New 5,6-Dihydro-2-pyrones from Goniothalamus sesquipedalis and Goniothalamus grifithii
Talapatra, Sunil K.,Basu, Dipankar,Deb, Tullika,Goswami, Shyamaprosad,Talapatra, Bani
, p. 29 - 34 (2007/10/02)
The leaves and twigs of Goniothalamus sesquipedalis Wall (Annonaceae) afford four new 6-(7,8-dihydrostyryl)-5,6-dihydro-2-pyrones, having in each case hydroxy and/or acetoxy functions at C-7 and C-8.The detailed high resolution PMR and other spectral analyses along with their chemical interconversions reveal their structures as 6-(7,8-dihydro-7,8-diacetoxystyryl)-5,6-dihydro-2-pyrone (II), 6-(7,8-dihydro-7-acetoxy-8-hydroxystyryl)-5,6-dihydro-2-pyrone (III), 6-(7,8-dihydro-7,8-dihydroxystyryl)-5,6-dihydro-2-pyrone (IV) and 6-(7,8-dihydro-7,8-dihydroxystyryl)-5,6-dihydro-5-hydroxy-2-pyrone (V).Compounds II, III and IV have also been isolated from the bark of Goniothalamus grifithii Hook.F and T.Thoms.The 7,8-erythro configuration is revealed for the above dihydropyrones from the coupling constants of the vicinal protons.Biogenetic considerations lead us to propose 6,7-threo and 7,8-erythro-configurations leading to 6(S), 7(S) and 8(S) configuration in these dihydropyrones.The stereochemistry of C-5 in V remains unsettled.
