Chbib C, Sobczak AJ, Mudgal M, Gonzalez C, Lumpuy D, Nagaj J, Stokowa-Soltys K, Wnuk SF.
S-Ribosylhomocysteine Analogues Modified at the Ribosyl C-4 Position.
J Sulphur Chem 2016;
37:307-327. [PMID:
27516805 DOI:
10.1080/17415993.2015.1137921]
[Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
4-C-Alkyl/aryl-S-ribosylhomocysteine (SRH) analogues were prepared by coupling of homocysteine with 4-substituted ribofuranose derivatives. The diastereoselective incorporation of the methyl substituent into the 4 position of the ribose ring was accomplished by addition of methylmagnesium bromide to the protected ribitol-4-ulose yielding the 4-C-methylribitol in 85% yield as single 4R diastereomer. The 4-C hexyl, octyl, vinyl, and aryl ribitols were prepared analogously. Chelation controlled addition of a carbanion to ketones from the (Si-face) was responsible for the observed stereochemical outcome. Oxidation of the primary alcohol of the 4-C ribitols with the catalytic amount of tetrapropylammonium perruthenate in the presence of N-methylmorpholine N-oxide produced 4-C-alkylribono-1,4-lactones in high yields. Mesylation of the latter compounds at the 5-hydroxyl position and treatment with a protected homocysteine thiolate afforded protected 4-C-alkyl/aryl-SRH analogues as the lactones. Reduction with lithium triethylborohydride and successive global deprotections with TFA afforded 4-C-alkyl/aryl SRH analogues. These analogues might impede the S-ribosylhomocysteinase(LuxS)-catalyzed reaction by preventing β-elimination of a homocysteine molecule, and thus depleting the production of quorum sensing signaling molecule AI-2.
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