The four unsaturated α-fluoro alcohols, 3-fluoro-1-[(p-tolyl)sulphinyl]hept-5-en-2-ols and 3-fluoro-6-methyl-1-[(p-tolyl)sulphinyl]hept-5-en-2-ols 3 having the (2S,3S,Rs) or (2S,3R,Rs) absolute configuration, gave the corresponding 6-methyl-or 6,6-dimethyl-substituted 5-chloromercurio-3-fluoro-2-[(p-tolyl)sulphinyl]tetrahydropyrans 5 and 6 and the 5-[1′-(chloromercurio)ethyl]-3-fluoro-2-[(p-tolyl)sulphinyl]tetrahydrofurans 4 by ‘endo’ or ‘exo’ cyclooxymercuriation promoted by mercury(II) trifluoroacetate. All the synthesized compounds have been isolated in optically pure form and their structure, absolute configuration, and preferred conformation have been established by 1H, 13C and 19F NMR studies. Elaboration of the chloromercurio and sulphinylmethyl substituents on a couple of diastereoisomeric tetrahydropyrans 6 allowed us to obtain the corresponding 3-fluoro-2-hydroxymethyltetrahydropyrans 11.
Homochiral fluoroorganic compounds. Part 17. 2-(p-Tolylsulphinylmethyl)-3-fluorotetrahydro-pyrans and -furans through intramolecular oxymercuriation
BRAVO, PIERFRANCESCO;RESNATI, GIUSEPPE;
1991-01-01
Abstract
The four unsaturated α-fluoro alcohols, 3-fluoro-1-[(p-tolyl)sulphinyl]hept-5-en-2-ols and 3-fluoro-6-methyl-1-[(p-tolyl)sulphinyl]hept-5-en-2-ols 3 having the (2S,3S,Rs) or (2S,3R,Rs) absolute configuration, gave the corresponding 6-methyl-or 6,6-dimethyl-substituted 5-chloromercurio-3-fluoro-2-[(p-tolyl)sulphinyl]tetrahydropyrans 5 and 6 and the 5-[1′-(chloromercurio)ethyl]-3-fluoro-2-[(p-tolyl)sulphinyl]tetrahydrofurans 4 by ‘endo’ or ‘exo’ cyclooxymercuriation promoted by mercury(II) trifluoroacetate. All the synthesized compounds have been isolated in optically pure form and their structure, absolute configuration, and preferred conformation have been established by 1H, 13C and 19F NMR studies. Elaboration of the chloromercurio and sulphinylmethyl substituents on a couple of diastereoisomeric tetrahydropyrans 6 allowed us to obtain the corresponding 3-fluoro-2-hydroxymethyltetrahydropyrans 11.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.