Studies on the Synthesis of Bafilomycin A<sub>1</sub>: Stereochemical Aspects of the Fragment Assembly Aldol Reaction for Construction of the C(13)−C(25) Segment
作者:William R. Roush、Thomas D. Bannister、Michael D. Wendt、Jill A. Jablonowski、Karl A. Scheidt
DOI:10.1021/jo016413f
日期:2002.6.1
lithium enolate aldol reaction. In contrast, the aldol reaction of 6a and the chlorotitanium enolates of 7a,c were much less sensitive to the nature of the C(15)-hydroxyl protecting group. Studies of the reactions of chiral aldehydes with Takai's (gamma-methoxyallyl)chromium reagent 40 are also described. The stereoselectivity of these reactions is also highly dependent on the protecting groups and stereochemistry
通过涉及手性醛6a和手性甲基酮7的片段组装醛醇缩合反应的途径,开发了对应于bafilomycin A(1)的C(13)-C(25)段的醛醇8a-c的高度立体选择性合成。在确定6a的关键醇醛偶联和7b的烯醇锂的立体选择性中,作用起关键作用。手性醛片段的C(23)-OH的保护基也会影响烯醇锂醛醇缩醛反应的选择性。相反,6a的醛醇缩合反应和7a,c的氯钛烯醇盐反应对C(15)-羟基保护基的性质的敏感度要低得多。还描述了手性醛与高井氏(γ-甲氧基烯丙基)铬试剂40的反应的研究。