The present invention relates to a kind of methods preparing 2O fucosyllactoses, can be by the purposes for the intermediate and these intermediates that this method obtains.The preparation include make logical formula (I) by shield fucose and three (C1‑C6Alkyl) silicyl Iod R to be to obtain being protected 1 iodo fucose then make to be protected 1 iodo fucose and be reacted in the presence of at least one alkali with logical formula (II) compound and deprotect gained coupled product, obtain 2O fucosyllactoses.Variable is respectively defined as follows:RaAnd RbIt is identical or different and be C (=O) C1‑C6Alkyl or C (=O) phenyl, wherein the phenyl is unsubstituted or optionally with 1 to 5 substituent group or RaAnd RbIt is group (C=O) or the methylene C (R of substitution togetherdRe), RcIt is group RSiOr benzyl, wherein the benzyl is unsubstituted or optionally with 1,2 or 3 substituent group, RSiIt is formula SiRfRgRhGroup, wherein Rf, RgAnd RhIdentical or different and e.g. C1‑C8Alkyl, R1It is group C (=O) R11Or group SiR12R13R14, R2It is identical or different, e.g. C1‑C8Alkyl;R3It is identical or different, and be such as C1‑C8Alkyl or two group R3Linear C is formed together1‑C4Alkylidene is unsubstituted or with 1 to 6 methyl as substituent group.
