127263-10-9Relevant academic research and scientific papers
Fluorinated acetylenes. Part 12. Reaction of 3,3,3-trifluoropropynyl-lithium with benzil and α-haloacetophenones
Barlow, Michael G.,Tajammal, Sabiha,Tipping, Anthony E.
, p. 139 - 149 (1993)
Treatment of 3,3,3-trifluoropropynyl-lithium (4) with benzil (2:1 molar ratio) in diethyl ether at -50 deg C, followed by addition of an excess of benzoyl chloride, affords 1-benzoyl-5-benzoyloxy-5-phenyl-2,3-bis(trifluoromethyl)cyclopenta-1,3-diene (11) (61percent) and the 1,4-dialkynyl ester (CF3CC)2CPhO2CPh (1b) (8percent).Similar reaction of the salt 4 with α-chloroacetophenone (2:1 molar ratio) in diethyl ether at -50 deg C, followed by addition of a slight excess of benzoyl chloride, gives the ester CF3CCCPh(CH2CI)O2CPh (14a) (55percent) and a compound considered to be 2,5-diphenyl-2,5-bis(3,3,3-trifluoropropynyl)-1,4-dioxan (15) (30percent).Under the same conditions, α-bromoacetophenone yields the corresponding bromo ester CF3CCCPh(CH2Br)O2CPh (14b) (39percent), 2-phenyl-2-(3,3,3-trifluoropropynyl)oxirane (16) (25percent) and the dialkynyl ester (1b) (7percent).The oxirane 16, conveniently prepared (51percent) by treatment of salt 4 with the bromoketone (1:1 molar ratio) in THF at -60 deg C, on reaction with lithium phenylacetylide followed by addition of benzoyl chloride (c. 1:1:1 molar ratio) in THF at -60 deg C gives a compound identified as 2-phenyl-2-(1-phenyl-5,5,5-trifluoropent-3-en-1-yn-3-yl)oxirane (17) or possibly 2-phenyl-2-(3-phenylprop-2-yn-1-yl)-3-(2,2,2-trifluoroethylidene)oxirane (18) in 28percent yield.
Fluorinated Acetylenes. Part 10. Cycloaddition of α,α-Bis(3,3,3-trifluoropropynyl)benzyl Benzoate and 1,1-Bis(3,3,3-trifluoropropynyl)ethyl Ethanoate with Furan and Cyclopentadiene
Barlow, Michael G.,Tajammal, Sabiha,Tipping, Anthony E.
, p. 2485 - 2494 (2007/10/02)
Reaction between furan and the dialkynyl ester (CF3CC)2CPhO2CPh 1a in dichloromethane at 50 deg C gave four rearranged 1:1 adducts, (Z)-5-(α-benzoyloxybenzylidene)-1,4-bis(trifluoromethyl)-8-oxa-tricyclonona-3,6-diene 11a (major product), 4-benzoyloxy-3,8-bis(trifluoromethyl)-1,1a,2,8c-tetrahydro-4H-1,2,8b-epoxymethenocyclopropafluorene 15, the corresponding 3H-compound 16 and 8,9-dibenzoyl-4,7-bis(trifluoromethyl)-2-oxatetracyclonon-7-ene 13a via the common intermediate 2-benzoyloxy-2-phenyl-4,10-bis(trifluoromethyl)-7-oxapentacyclodec-3-ene 8a formed from the Diels-Alder adduct by intramolecular ( ? 2 S + ? 2 S + ? 2 S ) cycloaddition.The corresponding reaction with the ester (CF3CC)2CMeO2CMe 1b gave analogously the diketone 13b (major product) and a mixture of the (E)- and (Z)-isomers of the triene 11b; a 2:1 adduct, 4-acetoxy-3-methyl-5,11-bis(trifluoromethyl)-8,15-dioxahexacyclopentadeca-2,13-diene 10 was also isolated.A mixture of cyclopentadiene and the ester 1a (2:1 molar ratio), heated at 50 deg C, yielded mainly the bis-Diels-Alder adduct α,α-bis(3-trifluoromethylbicyclohepta-2,5-dien-2-yl)benzylbenzoate 7a, together with the rearranged 1:1 adduct, diketone 13c.Similarly, the major product from the reaction of an excess of cyclopentadiene with ester 1b at 50 deg C was the bis-Diels-Alder adduct 7b, but a 1: 1 molar ratio of reactants at 20 deg C gave the mono Diels-Alder adduct 1-(3-trifluoromethylbicyclohepta-2,5-dien-2-yl)-1-(3,3,3-trifluoropropynyl)ethyl ethanoate 6d in high yield.The bis adduct 7a was stable at 50 deg C, but the mono adduct 6d underwent slow intramolecular ( ? 2 S + ? 2 S + ? 2 S ) cycloaddition, cf., the furan reactions, and the intermediate 8d so formed rearranged to a mixture of 8,9-diacetyl-4,7-bis(trifluoromethyl)tetracyclonon-7-ene 13d and 1-acetoxy-1-non-7-en-9-yl>ethene 18.In the presence of traces of water, the ketone 13d was only a minor product with the major products being the substituted ethene 18 and two diastereoisomers of 1-acetoxy-1-non-7-en-9-yl)ethanol 19.
