[reaction--see text] The butane-2,3-diacetal (BDA) desymmetrized glycolic acid building block 1 undergoes efficient and highly diastereoselective lithium enolate aldol reactions with both aromatic and aliphatic aldehydes to afford, after an acidic methanolysis deprotection step, the enantiopure anti-2,3-dihydroxy esters in good yield.
[反应-参见文本]
异丁烷2,3-二
缩醛(B
DA)
乙醇酸结构单元1与芳香族和脂肪族醛进行高效且高度非对映选择性的烯醇酸
锂醛醇
缩醛反应,从而在酸性
甲醇分解脱保护步骤后得到对映体纯的抗2,3-二羟基酯,收率良好。