N-Trifluoroacetyl Sialyl Phosphite Donors for the Synthesis of α(2 → 9) Oligosialic Acids
摘要:
A new method for the synthesis of alpha(2 -> 9) oligosialic acids is developed using phosphite sialyl donors that are protected with a C-5 N-trifluoroacetyl (NHTFA) substituent. Compared with conventional donors, these donors gave a higher degree of alpha-anomeric selectivity during glycosidic bond formation and better yields during iterative sialylation in the synthesis of oligosialic acids.
N-Trifluoroacetyl Sialyl Phosphite Donors for the Synthesis of α(2 → 9) Oligosialic Acids
摘要:
A new method for the synthesis of alpha(2 -> 9) oligosialic acids is developed using phosphite sialyl donors that are protected with a C-5 N-trifluoroacetyl (NHTFA) substituent. Compared with conventional donors, these donors gave a higher degree of alpha-anomeric selectivity during glycosidic bond formation and better yields during iterative sialylation in the synthesis of oligosialic acids.
Phosphite-based sialic acid donors in the synthesis of α(2→9) oligosialic acids
作者:Chang-Ching Lin、Avijit Kumar Adak、Jia-Cherng Horng、Chun-Cheng Lin
DOI:10.1016/j.tet.2009.04.022
日期:2009.6
The combination of a phosphite donor and an anomeric thiocresol-protected acceptor, both with a TFA protecting group at C-5 of the sialicacid, provides good α-selectivity and yield in sialylation. Although the convergent synthetic strategy of using a phosphite disialo-donor and a disialo-acceptor assembles tetra-sialic acid efficiently, overcoming the low α-selectivity of α-anomer and purifying it