Synthesis of the Stereoisomers of 1-O-(2'-Methoxyhexadecyl)glycerol and some Phosphocholine Derivatives.

Ether lipids

“…Indeed, the fragmentation pattern obtained from MS spectra of the 2 -methoxylated alkylglycerol derivatives after treatment with osmium tetroxide and subsequent methylation or trimethylsilylation, have been used to determine the position of the double bonds at the alkyl chain (Hallgren and Stallberg, 1967;Hallgren et al, 1971;Hayashi and Takagi, 1982). Finally, the information obtained from GLC and GLC-MS analyses together with NMR spectroscopy of 2 -methoxylated alkylglycerols from synthetic and natural origin have unambiguously confirmed the final structure of the most prevalent 2 -methoxylated alkylglycerols and their absolute configuration (Hallgren and Stallberg, 1967;Hallgren et al, 1971;Stallberg, 1990).…”

“…It was started with the regioselective opening of (R)-epichlorohydrin with tridec-1-ynyllithium, obtained by treatment with n-butyllithium, in the presence of boron trifluoride according to Yamaguchi and Hirao (1983), affording (R)-1-chlorohexadec-4-yn-2-ol 34 in 50% yields and 98% ee -sn-glycerol 14 in 99% yields and 27% overall yields from (R)-epichlorohydrin. The right stereochemistry of 14 was confirmed (Magnusson and Haraldsson, 2010) by firstly, comparing the 1 H NMR spectrum of 13, obtained by hydrogenation of 14, with that of 13 from literature (Stallberg, 1990), to confirm the type of diastereomer, and secondly, by comparison of the optical activities of the afforded 13 and 14 with those found in literature (Stallberg, 1975(Stallberg, , 1990, to confirm the type of enantiomer.…”

“…More recently the C16:0 and C16:1 methoxyl substituted alkylglycerols have been reported from the brachiopod Gryphus vitreus (D'Ambrosio et al, 1996). The absolute configuration of these peculiar alkylglycerol analogues was unknown for two decades after their discovery, until 1990, when Stallberg determined the R configuration at the carbon bearing the methoxyl group in the alkyl chain and the S configuration at the mid-positioned carbon atom of the glycerol moiety, implying their sn-1 configuration like the ordinary 1-O-alkyl-sn-glycerols and 1-O-(alk-1 -enyl)-sn-glycerol analogues (Stallberg, 1990). This was achieved by comparing the 1 H NMR spectra and optical activities of the four synthetic diastereomers of 1-O-(2 -methoxyhexadecyl)glycerol with those of the natural product.…”

“…Finally, hydrolysis of the acetonide with a mixture of ether and hydrochloric acid at 5 • C afforded the desired (Z)-1-O-(2 -methoxyhexadec-4 -enyl)glycerol 28 in 78% yield. Stallberg (1990) performed the first synthesis of the naturally occurring (2 R)-1-O-(2 -methoxyhexadecyl)-sn-glycerol enantiomerically pure via the two routes shown in Scheme 7 and 8. There, the chiral precursors (S)-1-benzyloxy-2,3-epoxypropane and (R)-2,3-O-isopropylidene-sn-glycerol were exploited.…”

A General Route to Mono- and Disubstituted Divinyl Sulfones: Acyclic Michael Acceptors for the Synthesis of Polyfunctionalized Cyclic Sulfones

“…To test the hypothesis, we targeted the synthesis of two triose derived divinyl sulfones 10 and 13 (Scheme ). Thus the synthesis started from the easily available monotosylated and partially protected glycerol derivative 7a , , which was treated with mercaptoethanol in the presence of tetramethylguanidine (TMG) at an elevated temperature to obtain the sulfide 8 contaminated with inseparable materials. The impure sulfide 8 was therefore oxidized directly with magnesium monoperoxyphthalate hexahydrate (MMPP) to the corresponding sulfone 9 , which was isolated in pure form in 78% overall yield in two steps.…”