124568-12-3Relevant academic research and scientific papers
Stereoselective synthesis of fluorinated isoxazolidines and 2,3- dihydroisoxazoles: A cycloadditive route to enantiomerically pure amino fluoro alcohols
Bruché, Luca,Arnone, Alberto,Bravo, Pierfrancesco,Panzeri, Walter,Pesenti, Cristina,Viani, Fiorenza
, p. 1665 - 1670 (2007/10/03)
3-(Fluoroalkyl)isoxazolidines 6 and -2,3-dihydroisoxazoles 8 have been obtained in enantiomerically pure form with good diastereoselectivity by 1,3- dipolar cycloaddition of diethyl fumarate and dimethylacetylene dicarboxylate, respectively, to the chiral fluorinated nitrone (R)-5. The latter has been prepared from the β-fluoromethyl-β-oxo sulfoxide (R(S)-1, by a synthetic sequence where the chiral and enantiomerically pure sulfinyl function acts as a removable source of chirality. Reductive opening of isoxazolidines 6 then afforded amino fluoromethyl diols 7 in good yields.
Homochiral Fluoro-organic Compounds. Part 12. α-Hydroxy β-Fluoro Aldehydes and Esters, Fluoro Epoxides and Glycols from Fluorinated Sulphinyl Chirons
Bravo, Pierfrancesco,Piovosi, Elena,Resnati, Giuseppe
, p. 1201 - 1208 (2007/10/02)
α-Fluoro α'-sulphinyl ketones carrying an α'-alkyl or α'-aryl substituent have been reduced with high 1,2- or 1,3-induced diastereoselectivity to give the corresponding α-fluoro α'-sulphinyl secondary alkohols.The chiral sulphinyl auxiliary agent was removed by first selective reduction to a thio group, then by methylation to a sulphonium ion and finally through SN2 removal by the adjacent secondary alcohol.It is therefore possible to obtain, in an optically pure form, α-fluoro epoxides which are chiral at both the carbon atoms of the oxirane ring, or at the α-fluorinated carbon and at adjacent oxirane carbon.Furthermore, homochiral α-fluorinated vicinal glycols, β-fluoro α-hydroxy aldehydes, and β-fluoro α-hydroxy esters, which may contain the fluorohydrin moiety with syn or anti relative stereochemistry, have been obtained in an optically pure form from the corresponding α-fluoro α'-sulphinyl secondary alcohols by use of the varied reactivity of the sulphinyl group.
