کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5216486 1383266 2013 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
NaBH3CN and other systems as substitutes of tin and silicon hydrides in the light or heat-initiated reduction of halosugars: a tunable access to either 2-deoxy sugars or 1,5-anhydro-itols
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
NaBH3CN and other systems as substitutes of tin and silicon hydrides in the light or heat-initiated reduction of halosugars: a tunable access to either 2-deoxy sugars or 1,5-anhydro-itols
چکیده انگلیسی

UV light-promoted reduction of acetobromoglucose by NaBH3CN in t-BuOH afforded 1,3,4,6-tetra-O-acetyl-2-deoxy-α-d-arabino-hexopyranose in high yield and purity, via a Surzur-Tanner rearrangement, while, with 10 mol % thiophenol added, acetylated 1,5-anhydro-d-glucitol was cleanly obtained. Such tin-free and mild reductions, presumed to proceed via radical pathways, were more efficient with NaBH3CN compared to NaBH4 or NaBD4, and do not occur with acetochloroglucose. Similar reductions to 1,3,4,6-tetra-O-acetyl-2-deoxy-α-d-arabino-hexopyranose were achieved upon heating to 80 °C t-BuOH or CH3CN solutions of NaBH3CN and AIBN, but with a lower selectivity due to competing ionic reactions. With other pyranosyl bromides, reductions by NaBH3CN could be tuned similarly (d-galacto), but some (d-manno, 5-thio-d-xylo) gave mainly or exclusively 1,5-anhydro-itols. Other conditions, or reagents promoting SET process, afforded also reduced products, but with lower rates or selectivities. Primary iodides were reduced readily with NaBH3CN under UV light.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Tetrahedron - Volume 69, Issue 46, 18 November 2013, Pages 9656-9662
نویسندگان
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