Enantioselective Syntheses of Ring-C Precursors of Vitamin B12. Substrate Control. A Novel Si-Assisted Elimination of Vinyl Bromides
摘要:
[GRAPHICS]Homochiral ring-C precursors 34 of Vitamin B-12 have been prepared by Ireland-Claisen rearrangement of allyl esters 32, followed by a novel Si-assisted elimination of HBr.
Enantioselective Syntheses of Ring-C Precursors of Vitamin B12. Substrate Control. A Novel Si-Assisted Elimination of Vinyl Bromides
摘要:
[GRAPHICS]Homochiral ring-C precursors 34 of Vitamin B-12 have been prepared by Ireland-Claisen rearrangement of allyl esters 32, followed by a novel Si-assisted elimination of HBr.
An improved synthesis of a ring-C precursor to cobyric acid
作者:Peter Alan Jacobi、Hui Wang
DOI:10.3998/ark.5550190.0011.403
日期:——
Alkyne acid 10 was prepared in enantioselective fashion from allylic ester derivative (R)-18 via an E-selective Ireland-Claisen rearrangement followed by Si-assisted elimination of HBr. The present route offers significant advantages in terms of both scalability and overall yield compared to that previously described. Alkyne acid 10 is an attractive ring-Cprecursor for an ongoing synthesis of cobyric
炔酸 10 是以对映选择性方式从烯丙基酯衍生物 (R)-18 通过 E 选择性爱尔兰-克莱森重排和 Si 辅助消除 HBr 制备的。与先前描述的路线相比,本路线在可扩展性和总产量方面提供了显着优势。炔酸 10 是一种有吸引力的 C 环前体,用于正在进行的钴酸合成。
Enantioselective Syntheses of Ring-C Precursors of Vitamin B<sub>12</sub>. Substrate Control. A Novel Si-Assisted Elimination of Vinyl Bromides
作者:Peter A. Jacobi、Carlos Tassa
DOI:10.1021/ol036061u
日期:2003.12.1
[GRAPHICS]Homochiral ring-C precursors 34 of Vitamin B-12 have been prepared by Ireland-Claisen rearrangement of allyl esters 32, followed by a novel Si-assisted elimination of HBr.