STUDIES ON NUCLEOSIDES .5. TOTAL SYNTHESI S OF DIACETYL NEOSIDOMYCIN

The diacetate of neosidomycin had been synthesized by indoline - indol e method. Firstly, indoline - 3 - acetamide (9) was prepared from indo le - 3 - acetic acid by catalytic hydrogenation, esterification and am inolysis. And then methyl 1, 2, 3, - O - triacetyl - 4 - deoxy - beta - D - ribo - hexopyranuronate(6) was synthesized from 4 - deoxy - D - ribo - hexopyranose (3) through triphenylmethylation, acetylation, det riphenylmethylation, oxidation and esterification. The indoline - N - glycoside 10 was obtained by the condensation of 9 and 6. Finally, the diacetate of neosidomycin 2 (methyl[1 - (3 - carbamoylmethylindoyl) - 2, 3 - O diacetyl - 4 - deoxy - D-ribo - hexopyranoside] uronate), wa s prepared by the dehydrogenation of 10 with DDQ. With the similar met hod 1 - (3 - carbamoylmethylindoyl) - 2, 3, 4, 6 - O - tetraacetyl- be ta - D - glucopyranoside (13) was synthesized.