Novel synthesis of 2-(trifluoromethyl)- and 2-(perfluoroalkyl)-2-hydroxy-2H-chromenes and their regiospecific reaction with silyl enol ethers.
The synthesis of substituted 2-(trifluoromethyl)- and 2-(perfluoroalkyl)-2-hydroxy-2H-chromenes 2a-o was achieved in good yields by intramolecular cyclization of 3-(perfluoroalkyl)-3-phenoxypropenals 1 in the presence of aluminum chloride. Then a Lewis acid mediated nucleophilic reaction with silyl enol ethers 3 proceeded with complete regiospecificity to afford 4-functional 2-(trifluoromethyl)- and 2-(perfluoroalkyl)-4H-chromenes 4a-p with high yields.
El Kharrat
Salem
S
Organisation Moléculaire, Evolution et Matériaux Fluorés, cc17, Université Montpellier II, UMR CNRS 5073, Place E. Bataillon, 34095 Montpellier Cedex 05, France.
Laurent
Philippe
P
Blancou
Hubert
H
D001578:Benzopyrans / Q000138:chemical synthesis* / Q000737:chemistry*; D004987:Ethers / Q000737:chemistry*; D015394:Molecular Structure; D013237:Stereoisomerism; D014297:Trimethylsilyl Compounds / Q000737:chemistry*
D001578:Benzopyrans; D004987:Ethers; D014297:Trimethylsilyl Compounds