已开发了一种基于Sharpless不对称环氧化的通用,不饱和的α-氨基酸的非烷基化对映体选择性合成方法。制备带有不饱和取代基的对映体富集的反式环氧醇,并用对甲氧基苄胺作为亲核试剂进行区域和立体特异性开环,得到抗-3-(对甲氧基苄基氨基)-1,2-二醇,并进一步受到保护。用Boc反应2 O. 1,2-二醇片段然后通过氧化一个顺序处理裂解用高碘酸钠和亚氯酸钠,得到相应的氨基酸。使用这种方法,双重受N保护(p-甲氧基苄基和Boc)烯丙基甘氨酸,3-丁烯基甘氨酸和4-戊烯基甘氨酸已经通过三个合成步骤由相应的烯丙醇制备。为了证明氮保护的正交性质,已经从完全保护的氨基酯中选择性地除去了两个保护基。
The total synthesis of leukotrienes has been achieved starting from butadiene by a palladium-catalyzed telomerization at room temperature. A Sharpless catalytic asymmetric epoxidation generated the asymmetric centers with >94% ee. Simple transformations of the key intermediate 15 produced the leukotrienes LTA4 methyl ester (4), LTC4 (1), LTD4 (2) and LTE4 (3), as well as (14S,15S)-LTA4 methyl ester (24)
A stereoselectivesynthesis of normethyl C1-C13 fragment of bistramide A is described. The key steps involve an asymmetric Sharpless epoxidation, a cross-metathesis reaction and an intramolecular oxa-Michael reaction. The trans-2,6-disubstituted tetrahydropyran subunit has been synthesized in an overall yield of 7% with 96% ee. The cis isomer was prepared by a similar pathway with the same efficiency
描述了双链酰胺 A 的正甲基 C1-C13 片段的立体选择性合成。关键步骤包括不对称 Sharpless 环氧化、交叉复分解反应和分子内 oxa-Michael 反应。已以 7% 的总产率和 96% 的 ee 合成了反式-2,6-二取代的四氢吡喃亚基。顺式异构体通过类似的途径制备,具有相同的效率和对映选择性。
Miftakhov, M. S.; Tolstikov, A. G.; Tolstikov, G. A., Journal of Organic Chemistry USSR (English Translation), 1984, vol. 20, # 3, p. 618 - 622
作者:Miftakhov, M. S.、Tolstikov, A. G.、Tolstikov, G. A.
DOI:——
日期:——
PAGE, PHILIP C. BULMAN;RAYNER, CHRISTOPHER M.;SUTHERLAND, IAN O., J. CHEM. SOC. PERKIN TRANS. PT 1,(1990) N, C. 1375
作者:PAGE, PHILIP C. BULMAN、RAYNER, CHRISTOPHER M.、SUTHERLAND, IAN O.