中文名称 | 英文名称 | CAS号 | 化学式 | 分子量 |
---|---|---|---|---|
—— | methyl 4,6-O-(4-methoxybenzylidene)-α-D-galactopyranoside | 185754-26-1 | C15H20O7 | 312.32 |
Α-D-乳酸吡喃糖苷甲酯 | methyl α-D-galactopyranoside | 3396-99-4 | C7H14O6 | 194.185 |
中文名称 | 英文名称 | CAS号 | 化学式 | 分子量 |
---|---|---|---|---|
—— | (2S,3R,4S,5S,6S)-3,4-Bis-benzyloxy-2-methoxy-5-(4-methoxy-benzyloxy)-6-((2R,3S)-3-methyl-oxiranyl)-tetrahydro-pyran | 131750-91-9 | C31H36O7 | 520.623 |
—— | (2S,3R,4S,5S,6S)-3,4-Bis-benzyloxy-2-methoxy-5-(4-methoxy-benzyloxy)-6-((2S,3R)-3-methyl-oxiranyl)-tetrahydro-pyran | 131750-90-8 | C31H36O7 | 520.623 |
A variety of approaches towards the synthesis of lincosamine, a derived portion of the antibiotic lincomycin , are reported. Initial approaches involved the intramolecular delivery of a nitrogen atom ( trichloroacetimidate , trichloroacetylcarbamate , carbamate, 2-amino-2- phenylacetate ) attached to O4 onto C6 of a 6,7-anhydrooctoside. Later approaches, albeit more direct but again largely unsuccessful, involved the Sharpless titanium(IV)-mediated nucleophilic opening of a suitable 6,7-anhydrooctose, and the Sharpless oxyamination and the aziridination of suitable octenoses . As an aid to the structure elucidation of several compounds encountered in this work, single-crystal X-ray structure determinations are reported for methyl 6,7-anhydro-2,3-di-O-benzyl-8-deoxy-α-D-threo-D-galacto-octopyranoside , methyl 6,7-anhydro-2,3-di-O-benzyl-8-deoxy-α-D-threo-D-gluco-octopyranoside and 7-azido-7-deoxy-1,2:3,4-di-O-isopropylidene-β-L-erythro-Dgalacto-octose.
Methyl (E)-2,3-di-O-benzyl-6,7,8-trideoxy-α-D-galacto-oct-6-enopyranoside, a potential precursor to lincosamine, has been prepared from both methyl α-D-galactopyranoside and methyl α-D-glucopyranoside, with the required inversion at C4 in the latter sequence being effected by a conventional oxidation-reduction. As well, (E)-6,7-dideoxy-1,2: 3,4-di-O-isopropylidene-α-D-galacto-oct-6-enose and (E)- and (Z)-6,7,8- trideoxy-1,2:3,4-di-O-isopropylidene-α-D-galacto-oct-6-enose have been prepared from 1,2: 3,4-di-O-isopropylidene-α-D-galactose.