Stereoselective synthesis of (2S,3S,4Z)-4-fluoro-1,3-dihydroxy-2-(octadecanoylamino)octadec-4-ene, [(Z)-4-fluoroceramide], and its phase behavior at the air/water interface

Abstract

Background

Site‐Selective trans‐Hydrostannation of 1,3‐ and 1,n‐Diynes: Application to the Total Synthesis of Typhonosides E and F, and a Fluorinated Cerebroside Analogue

“…To illustrate the versatility of the tin residue as a handle for late‐stage modification, we targeted the corresponding alkenyl fluoride 31 (Scheme ). A number of fluorinated sphingolipids are known in the literature, but we are aware of a single example in which the fluorine atom had been placed at an olefinic site . Monolayers of this compound at an air/water interface showed higher stability than monolayers of its non‐fluorinated analogue; this observation might imply that the properties of biological membranes can also be modulated by incorporation of fluorinated glycolipids .…”

“…A number of fluorinated sphingolipids are known in the literature, but we are aware of a single example in which the fluorine atom had been placed at an olefinic site . Monolayers of this compound at an air/water interface showed higher stability than monolayers of its non‐fluorinated analogue; this observation might imply that the properties of biological membranes can also be modulated by incorporation of fluorinated glycolipids . The literature route had introduced the fluorine label in the very first step and carried it through the entire sequence from there on .…”

“…Monolayers of this compound at an air/water interface showed higher stability than monolayers of its non‐fluorinated analogue; this observation might imply that the properties of biological membranes can also be modulated by incorporation of fluorinated glycolipids . The literature route had introduced the fluorine label in the very first step and carried it through the entire sequence from there on . Our approach is conceptually different in that product 31 was prepared by late‐stage fluorination, wherein the tin atom of 25 was replaced with retention of the double bond configuration on treatment with F‐TEDA‐PF 6 in the presence of bench‐stable silver phosphinate (AgOP(O)Ph 2 ); as previously shown by our group, the use of this essentially neutral and non‐nucleophilic promotor is essential for success, although competing protodestannation could not be fully suppressed in this particular case, probably because access of the rather bulky fluorinating agent to the congested metalated site in 25 is disfavored.…”

Synthesis of new ligands for targeting the S1P1 receptor

“…24 The mixture of the diastereomeric fluoroallylic alcohols 54 was synthesized by Wittig reaction of tetradecanal and the phosphoniumbromide 52 followed by the reduction of the resulting unsaturated esters 53. The ratios of E/Z-isomers were determined by GC or 19 F NMR spectroscopy.…”

Stereoselective Synthesis of Fluorinated and Nonfluorinated Triazolo Analogues of Ceramides

“…11,12 Recently, we reported on the synthesis of enantiopure 4fluoroceramide and the influence of a single vinylic fluorine substituent on its phase behavior at the air/water interface. 13 In the present paper, the asymmetric synthesis of enantiomeric fluorinated and nonfluorinated analogues of natural ceramides bearing a triazolo moiety instead of the amide group is described ( Figure 2). These compounds are currently subjected to biochemical and biophysical investigations and the results will be reported elsewhere in due course.…”