作者:Ren� Csuk、Martin Hugener、Andrea Vasella
DOI:10.1002/hlca.19880710314
日期:1988.5.4
A new synthesis of N-acetylneuraminic acid (Neu5Ac; 28) via aldehyde 10 is described. The aldehyde 10 was obtained from N, acetyl-D-glucosamine (11; 5 steps, overall yield ca. 6%) or from D-glucono-1,5-lactone (17; 6 steps, overll yield ca 57%). Thus, on the one hand, N-acetyl-D-mannosamine (12), obtained from 11, was transformed into the known dithioacetal 14 and hence into the (ethylthio)dihydrooxazole
描述了经由醛10的N-乙酰神经氨酸(Neu5Ac;28)的新合成。从N,乙酰基-D-葡糖胺(11; 5步,总产率约6%)或从D-葡萄糖基-1,5-内酯(17; 6步,总产率约57%)获得醛10。因此,一方面,将由11获得的N-乙酰基-D-甘露糖胺(12)转化为已知的二硫缩醛14,并因此转化为(乙硫基)二氢恶唑16,其在弱酸性条件下裂解为醛。10。另一方面,将由17得到的已知酯18进行磺酰化并通过叠氮化物20进一步转化为N-乙酰基-D-甘露酸酯22。减少22至23和氧化23与“高碘”再次给了10。用由2-(溴甲基)丙烯酸叔丁酯(2)制得的有机锌试剂8处理醛10,主要得到24,将其转化(2-步)成2-亚甲基-D-。甘油-壬酸27,因此变成Neu5Ac(28)。