Deoxy-nitrosugars 15th communication Synthesis ofN-acetylneuraminic acid andN-acetyl-4-epineuraminic Acid
作者:Franz Baumberger、Andrea Vasella
DOI:10.1002/hlca.19860690528
日期:1986.7.30
A synthesis of N-acetylneuraminic acid (1) and of N-acetyl-4-epineuraminic acid (2, R = H) from 2-acetamido-4,6-O-benzylidene-1,2-dideoxy-1-nitro-D-mannopyranose (3) and 2-acetamido-1,2-dideoxy-4,6-O-isopropylidene-1-nitro-D-mannopyranose (4), respectively, is described. Michael addition of 3 and 4 to tert-butyl 2-(bromomethyl)prop-2-enoate (5) and subsequent hydrolytic removal of the NO2 group gave
的合成Ñ -acetylneuraminic酸(1)和ñ -乙酰基-4- epineuraminic酸(2,R = H)从2-乙酰氨基-4,6- ø -亚苄基-1,2-二脱氧-1-硝基分别描述了D-甘露吡喃糖(3)和2-乙酰氨基-1,2-二脱氧-4,6- O-异亚丙基-1-硝基-D-甘露吡喃糖(4)。迈克尔加成的3和4,以叔丁基2-(溴甲基)丙-2-烯酸酯(5)和随后的水解去除的NO的2组,得到4- nonulosonate互变异构体6 / 7和8 / 9,分别为(方案)。的立体选择性还原6 / 7和8 / 9用NaBH 4在二恶烷/ AcOH中/ H 2 ö得到12/13(94:6)和14/15分别:(8 92)。的还原6 / 7和8 / 9在不存在的AcOH或在EtOH,得到12 / 13(15:85)和14 / 15(15:85)中。臭氧分解12和13然后水解,分别得到神经氨酸叔丁酯