Add time:09/08/2019         Source:sciencedirect.com

Publisher SummaryThis chapter discusses the preparation of amino sugars and amino cyclitols through cyclization of dialdehydes with nitromethane. Two new asymmetric carbon atoms are formed in the cyclization step, a third on the acidification of the aci-nitro salt; thus, depending on the type of dialdehyde used, six or eight diastereomeric nitrodiols can be expected a priori. Stereochemical preference in the cyclization step giving equatorial hydroxyl groups preponderantly and stereospecificity in the acidification step giving an equatorial nitro group usually result in one major product—all equatorial—while another one to three isomers occur to a minor extent. Because of this stereoselectivity, only aminocyclitols and amino sugars with an equatorial amino function can be synthesized by this method. Cyclization of the dialdehyde with nitromethane—3–5 molar excess—in methanol or ethanol is usually effected in the presence of one molar equivalent of sodium methoxide or sodium ethoxide for 1–6 hours at 0°–25°.

We also recommend Trading Suppliers and Manufacturers of Methyl 3-deoxy-β-L-erythro-pentopyranoside (cas 19773-91-2). Pls Click Website Link as below: cas 19773-91-2 suppliers