Institute of Organic Chemistry of Polish Academy of Sciences, Warsaw, Poland.
J Antibiot (Tokyo). 2013 Mar;66(3):161-3. doi: 10.1038/ja.2013.8.
A novel, practical and stereoselective synthesis of (3R,4R)-4-acetoxy-3-[(R)-1-(t-butyldimethylsilyloxy)ethyl]-2-azetidinone, a key intermediate in the preparation of β-lactam antibiotics is reported. The crucial step of the synthesis is based on the Cu(I)-mediated Kinugasa cycloaddition/rearrangement cascade between silyl protected (R)-3-butyn-2-ol and the nitrone derived from benzyl hydroxylamine and benzyl glyoxylate. The obtained adduct is subjected to debenzylation with sodium, or lithium in liquid ammonia followed by oxidation with lead tetraacetate to afford the final product.
报道了一种新型、实用且立体选择性的（3R,4R）-4-乙酰氧基-3-[(R)-1-（叔丁基二甲基甲硅烷基氧基）乙基]-2-氮杂环丁酮的合成方法，该化合物是制备β-内酰胺抗生素的关键中间体。合成的关键步骤基于 Cu（I）介导的硅基保护（R）-3-丁炔-2-醇与苯甲羟胺和苯甲酰基甘氨酸衍生的硝酮之间的 Kinugasa 环加成/重排级联反应。得到的加成物用钠或液氨中的锂进行脱苄基化，然后用四乙酸铅氧化得到最终产物。
