95340-93-5Relevant articles and documents
Characterization of novel isobenzofuranones by DFT calculations and 2D NMR analysis
Teixeira, Milena G.,Alvarenga, Elson S.
, p. 623 - 631 (2016/08/26)
Phthalides are frequently found in naturally occurring substances and exhibit a broad spectrum of biological activities. In the search for compounds with insecticidal activity, phthalides have been used as versatile building blocks for the syntheses of novel potential agrochemicals. In our work, the Diels–Alder reaction between furan-2(5H)-one and cyclopentadiene was used successfully to obtain (3aR,4S,7R,7aS)-3a,4,7,7a-tetrahydro-4,7-methanoisobenzofuran-1(3H)-one and (3aS,4R,7S,7aR)-3a,4,7,7a-tetrahydro-4,7-methanoisobenzofuran-1(3H)-one (2) and (3aS,4S,7R,7aR)-3a,4,7,7a-tetrahydro-4,7-methanoisobenzofuran-1(3H)-one and (3aR,4R,7S,7aS)-3a,4,7,7a-tetrahydro-4,7-methanoisobenzofuran-1(3H)-one (3). The endo adduct (2) was brominated to afford (3aR,4R,5R,7R,7aS,8R)-5,8-dibromohexahydro-4,7-methanoisobenzofuran-1(3H)-one and (3aS,4S,5S,7S,7aR,8S)-5,8-dibromohexahydro-4,7-methanoisobenzofuran-1(3H)-one (4) and (3aS,4R,5R,6S,7S,7aR)-5,6-dibromohexahydro-4,7-methanoisobenzofuran-1(3H)-one and (3aR,4S,5S,6R,7R,7aS)-5,6-dibromohexahydro-4,7-methanoisobenzofuran-1(3H)-one (5). Following the initial analysis of the NMR spectra and the proposed two novel unforeseen products, we have decided to fully analyze the classical and non-classical assay structures with the aid of computational calculations. Computation to predict the 13C and 1H chemical shifts for mean absolute error analyses have been carried out by gauge-including atomic orbital method at M06-2X/6-31+G(d,p) and B3LYP/6-311+G(2d,p) levels of theory for all viable conformers. Characterization of the novel unforeseen compounds (4) and (5) were not possible by employing only the experimental NMR data; however, a more conclusive structural identification was performed by comparing the experimental and theoretical 1H and 13C chemical shifts by mean absolute error and DP4 probability analyses. Copyright
Microbial alcohol dehydrogenase screening for enantiopure lactone synthesis: Down-stream process from microtiter plate to bench bioreactor
Boratyński,Pannek,Walczak,Janik-Polanowicz,Huszcza,Szczepańska,Martinez-Rojas,Olejniczak
, p. 1637 - 1646 (2015/02/05)
One-pot conversion with whole cells of bacteria was performed for biooxidation of meso monocyclic (3a-b) and bicyclic diols (3c-e) into corresponding chiral lactones of bicyclo[4.3.0]nonane structure (2a-b) as well as exo- and endo-bridged lactones with the structure of [2.2.1] (3c-d) and [2.2.2] (3e). Micrococcus sp. DSM 30771 was selected as biocatalyst with significant alcohol dehydrogenase activity. Among tested strains, microbial oxidation of meso diols 3a-e catalyzed by Micrococcus sp. afforded enantiomerically pure ((+)-(2S,3R)-2c (ee = 99%), (+)-(2S,3R)-2e (ee = 99%)) or enriched ((+)-(1S,5R)-2a (ee = 90%), (-)-(1S,5R)-2b (ee = 86%), (+)-(2S,3R)-2d (ee = 80%)) lactone moieties. Comparative study with respect to microbial cultivation as well as biooxidation was undertaken to verify agreement of secondary metabolite biosynthesis in different scales: from MTP (4 mL), across shake flask (100 mL) till bioreactor (4 L). The results from biotransformations showed quite similar dependence in oxidation of all substrates 3a-e in MTP and flasks as well, thereby confirmed the validity and reasonable approach of using MTP for preliminary studies.
Dimethylaluminum methide complex Tf2CHAlMe2: an effective catalyst for Diels-Alder reaction of α,β-unsaturated lactone derivatives with cyclopentadiene
Yanai, Hikaru,Takahashi, Arata,Taguchi, Takeo
, p. 12149 - 12159 (2008/02/10)
Lewis acid derived by mixing Tf2CH2 and Me3Al was found to be an effective catalyst system for the catalytic DA reaction of less reactive α,β-unsaturated lactone derivative with cyclopentadiene (CP). In this catalyst system, Tf2CHAlMe2 is an active species and an excess amount of Me3Al plays an important role to lower the catalyst loading. Substituent effect of the lactone framework on π-facial selectivity was also examined. In the reactions of both γ-substituted 5-membered lactone derivatives and γ- or δ-methylated 6-membered lactone derivatives with CP, selective attack on the anti face of γ- or δ-substituent was observed. On the other hand, in the cases of γ- or ε-methylated 7-membered lactone derivatives, CP favorably attacked on the syn face.
