Organoboron compounds in organic synthesis. 4. Asymmetric aldol reactions
Organoboron compounds in organic synthesis. 4. Asymmetric aldol reactions
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有机合成中的有机硼化合物。
DOI：
10.1021/ja00286a036
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发表时间：
1986
影响因子：
15
通讯作者：
T. Wollmann
中科院分区：
文献类型：
--
作者：
S. Masamune;Tsuneo Sato;ByeongMoon. Kim;T. Wollmann
无论是反和> 7 T-3-羟基-2-（甲基羰基）单元（1和2）经常嵌入丙酸盐来源的天然产物如大环内酯类抗生素中。123自从1981年几种手性硼烯醇化物试剂如3a 2a和4，2b问世以来，双不对称羟醛缩合法已被广泛用于合成顺式单元2，1，3，但反式单元1的合成方法仍有待探索。4为此，我们在此记录了一种新的试剂5a，它是反选择性的，并且在与典型醛的反应中始终达到大于80：1的对映选择性。5对这种对映体选择性的机理原理也进行了简要的讨论，从3a，3b，5a和5 b获得的结果。试剂3b和5 b分别不是3a和5a的类似物。6
Both the anti-and¿> 7t-3-hydroxy-2-(methylcarbonyl) units (1 and 2) are frequently embedded in natural products of propionate origin such as macrolide antibiotics. 1 23Since the advent of several chiral boron enolate reagents in 1981, eg, 3a2a and 4, 2b the double-asymmetric aldol methodology has been widely used for the efficient construction of the syn unit 2, 1, 3 but the same synthetic methodology still remains to be explored for the antiunit l. 4 For this purpose we record herein a new reagent 5a which is anti selective and consistently achieves an enantioselection of more than 80: 1 in reactions with typical aldehydes. 5 A mechanistic rationale for this enantioselectivity is alsopresented with a brief discussion on the results obtained from 3a, 3b, 5a, and 5b. The reagents 3b and 5b are nor analogues of 3a and 5a, respectively. 6