A Facile Synthesis of 2-Deoxy-2,3-didehydroneuraminic Acid Derivatives.

Abstract

The 2-thio- or 2-selenoglycosides of N-acetylneuraminic acid methyl ester were transformed by successive treatment with dimethyl(methylthio)sulfonium triflate (DMTST) and 1,8-diazabicyclo[5.4.0]-7-undecene (DBU) to give the corresponding methyl 2-deoxy-2,3-didehydroneuraminates in excellent yields. Their acids and their analogues are sialidase inhibitors of pharmaceutical interest.

Sialic Acid Derivative Synthesis and Inhibitory Activities against Human Parainfluenza Virus Type 1

“…C-4 modified Neu5Ac2en derivative 9a-d was synthesized as shown in Scheme 1. After a cyanomethyl group was selectively introduced at the C-4 alcohol of 16 and after the isopropylidene group was successively removed followed by acetylation, compound 18 was transformed by treatment with dimethyl(methylthio)sulfonium triflate (DMTST and DBU) (16) to develop compound 12. Intermediate 12 in turn was transformed into 9a-c.…”

Investigation into an efficient synthesis of 2,3-dehydro-N-acetyl neuraminic acid leads to three decarboxylated sialic acid dimers

“…The product was slightly unstable at room temperature at both dry and as CDCl 3 solution, and was found to decompose to the 2 monomer units. All HMBC correlations were recorded using a coupling constant of 8 Hz 13 neuraminyl]-2,4-dideoxy-a-D Dgalacto-octopyranose (10). Isolated yield is 13 mg (1%) as a yellow glassy oil.…”

One-pot SSA-catalyzed β-elimination: an efficient and inexpensive protocol for easy access to the glycal of sialic acid

“…Because of the synthetic importance of 9 , several methods have been developed to expedite or simplify its preparation, including β-elimination of 3 using TMSOTf or BF 3 .Et 2 O, 26,27 β-elimination of 4 catalyzed by 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) 9 or Et 3 N, 28 oxidation 29 or elimination 30 of thioglycoside of 1 , and treatment of 4 with Na 2 HPO 4 in refluxing acetonitrile for 3 h. 31 Although the last method gave an almost quantitative yield, the preparation of 4 using neat acetyl chloride requires several days to complete. 10,30 In an attempt to cut down on synthetic steps, Gervay-Hague and co-workers performed a one-pot synthesis using pyridine and Ac 2 O to afford 9 in 21% yield.…”

“…10,30 In an attempt to cut down on synthetic steps, Gervay-Hague and co-workers performed a one-pot synthesis using pyridine and Ac 2 O to afford 9 in 21% yield. 32 Further attempts to improve access to 9 by the same group led to the use flash vacuum pyrolysis (FVP) at 390–420 °C.…”