Department of Bioscience, Graduate School of Science and Technology, Shizuoka University, Ohya 836, Suruga ward, Shizuoka 422-8529, Japan.
Carbohydr Res. 2010 Jan 26;345(2):230-4. doi: 10.1016/j.carres.2009.10.007. Epub 2009 Dec 2.
A novel synthesis of furanodictines A [2-acetamido-3,6-anhydro-2-deoxy-5-O-isovaleryl-D-glucofuranose (1)] and B [2-acetamido-3,6-anhydro-2-deoxy-5-O-isovaleryl-D-mannofuranose (2)] is described starting from 2-acetamido-2-deoxy-D-glucose (GlcNAc). The synthetic protocol is based on deriving the epimeric bicyclic 3,6-anhydro sugars [2-acetamido-3,6-anhydro-2-deoxy-D-glucofuranose (4) and 2-acetamido-3,6-anhydro-2-deoxy-D-mannofuranose (5)] from GlcNAc. Reaction with borate upon heating led to a facile transformation of GlcNAc into the desired epimeric 3,6-anhydro sugars. The C5 hydroxyl group of the 3,6-anhydro compounds 4 and 5 was regioselectively esterified with the isovaleryl chloride to complete the synthesis of furanodictines A and B, respectively. The targets 1 and 2 were synthesized in only two steps requiring no protection/deprotection.
从 2-乙酰氨基-2-脱氧-D-葡萄糖（GlcNAc）出发，描述了呋喃多辛 A [2-乙酰氨基-3,6-脱水-2-脱氧-5-O-异戊酰基-D-吡喃葡萄糖（1）]和 B [2-乙酰氨基-3,6-脱水-2-脱氧-5-O-异戊酰基-D-甘露呋喃糖（2）]的新颖合成方法。该合成方案基于从 GlcNAc 衍生出差向异构的双环 3,6-脱水糖[2-乙酰氨基-3,6-脱水-2-脱氧-D-吡喃葡萄糖（4）和 2-乙酰氨基-3,6-脱水-2-脱氧-D-甘露呋喃糖（5）]。加热时与硼酸盐反应，可使 GlcNAc 很容易转化为所需的差向异构 3,6-脱水糖。3,6-脱水化合物 4 和 5 的 C5 羟基与异戊酰氯进行区域选择性酯化，分别完成了呋喃多辛 A 和 B 的合成。目标物 1 和 2 仅需两步合成，无需保护/脱保护。
