کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1314130 | 1499338 | 2014 | 15 صفحه PDF | دانلود رایگان |

• The synthesis of 5-alkyl-3,4-difluorofuran-2(5H)-ones was developed.
• The first synthetic step was radical addition of ethers to 2,3,3-trifluoroacrylate.
• The effects of alkyl and fluoro substituents on lactonisation were studied.
• DFT calculations of the cyclisations of 4-hydroxyalkanoates were carried out.
• Cyclisations became more feasible with increasing number of alkyls at C5.
5-Alkyl-3,4-difluorofuran-2(5H)-ones were synthesised starting with radical addition of ethers to methyl 2,3,3-trifluoroprop-2-enoate, followed by alkyloxy bond cleavage, acid-catalyzed lactonisation and dehydrofluorination. For a study of substituent effects on lactonisation, methyl 4-bromo-2-chloro-2-fluorodecanoate and 2-chloro-2-fluoro-4,4-dimethoxybutanoate based on radical additions of methyl 2-bromo-2-chloro-2-fluoroacetate to oct-1-ene or vinyl acetate were prepared. DFT calculations of the transition state energies of the exo-trig cyclisations confirmed the observation that the ring closure became more feasible with increasing number of alkyls at C4 of the fluorinated 4-hydroxyesters.
The synthesis begins with radical addition of ethers to trifluoroacrylate, followed by ether bond clavage to form 4-hydroxyalkanoates, which cyclise under strong acid catalysis and afford the butenolides by dehydrofluorination.Figure optionsDownload as PowerPoint slide
Journal: Journal of Fluorine Chemistry - Volume 162, June 2014, Pages 45–59