Can I read Synthesis of Fluorescent 7,8,9‐Tri‐ O ‐acetyl‐ N ‐acetyl‐ and 4‐ O ‐Acetyl‐ N ‐acetylneuraminic Acid α‐Thioketosides on EtoBox?

Synthesis of Fluorescent 7,8,9‐Tri‐ O ‐acetyl‐ N ‐acetyl‐ and 4‐ O ‐Acetyl‐ N ‐acetylneuraminic Acid α‐Thioketosides by Andreas Roth; Hans Faillard is a Chemistry article available to read on EtoBox.

What is Synthesis of Fluorescent 7,8,9‐Tri‐ O ‐acetyl‐ N ‐acetyl‐ and 4‐ O ‐Acetyl‐ N ‐acetylneuraminic Acid α‐Thioketosides about?

## Abstract Two new fluorescent regioselective __O__‐acetylated __N__‐acetylneuraminic acid (Neu5Ac) thioketosides, 2α‐[4‐(dansylamino)phenylthio]‐7,8,9‐tri‐__O__‐acetyl‐__N__‐acetylneuraminic acid {2α‐[4‐(dansylamino)phenylthio]‐Neu5,7,8,9Ac~4~} (3) and 2α‐[4‐(dansylamino)phenylthio]‐4‐__O__‐acetyl‐__N__‐acetylneuraminic acid {2α‐[4‐(dansylamino)phenylthio]‐Neu4,5Ac~2~} (9) were synthesized. The synthesis of both derivatives started with the peracetylated benzyl ester 1 as precursor. The 7,8,9‐tri‐__O__‐acetylated compound was prepared by partial deacetylation of 1 with sodium methoxide or with hydrazine hydrate, followed by catalytic benzyl ester hydrogenolysis. – Complete Zemplén deacetylation of 1 gave the Neu5Ac benzyl ester thioketoside 4, which was converted into the 8,9‐isopropylidene‐protected compound 5. By carefully performed regioselective 4‐__O__‐acetylation with acetic anhydride/pyridine in dichloromethane we obtained the desired fluorescent 4‐__O__‐acetyl derivative 6 and the nonfluorescent sulfonacetamide 7 as byproduct. Acidic 8,9‐deprotection of 6 and finally catalytic hydrogenolysis of the benzyl ester 7 terminated this synthetic route, yielding 2α‐[4‐(dansylamin

Who reads Synthesis of Fluorescent 7,8,9‐Tri‐ O ‐acetyl‐ N ‐acetyl‐ and 4‐ O ‐Acetyl‐ N ‐acetylneuraminic Acid α‐Thioketosides?

Author

Andreas Roth; Hans Faillard

Publisher

John Wiley and Sons; Wiley (John Wiley & Sons); VCH Verlagsgesellschaft; Wiley (ISSN 0947-3440)

Published

1993

Language

DE

Field

Chemistry (Physical Sciences)