Nonracemic Homopropargylic Alcohols via Asymmetric Allenylboration with the Robust and Versatile 10-TMS-9-borabicyclo[3.3.2]decanes
作者:Chunqiu Lai、John A. Soderquist
DOI:10.1021/ol0476164
日期:2005.3.1
The asymmetric allenylboration of representative aldehydes with the stable, storable 1 is reported. Easily and efficiently prepared in either enantiomeric form from the air-stable crystalline 4 through simple Grignard procedures, 1 gives 6 cleanly. The latter is easily isolated in high yield and ee with predictable stereochemistry. The procedure also regenerates 4 for its direct conversion back to
作者:Paul T. O'Sullivan、Wilm Buhr、Mary Ann M. Fuhry、Justin R. Harrison、John E. Davies、Neil Feeder、David R. Marshall、Jonathan W. Burton、Andrew B. Holmes
DOI:10.1021/ja038353w
日期:2004.2.1
The totalsynthesis of octalactins A and B has been achieved in 15 steps (longest linear sequence) and 10% overall yield from commercially available materials. Key steps include the Paterson-Aldol reaction for the rapid assembly of the carbonate 46, methylenation of 46 and subsequent Claisen rearrangement of the corresponding alkenyl-substituted cyclic ketene acetal to provide the core unsaturated
八内酯 A 和 B 的全合成已通过 15 个步骤(最长的线性序列)和 10% 的市售材料总产率实现。关键步骤包括用于快速组装碳酸酯 46 的 Paterson-Aldol 反应、46 的亚甲基化和随后相应烯基取代的环烯酮缩醛的 Claisen 重排以提供核心不饱和中环内酯 47,以及使用酶-在中环内酯存在下介导的乙酸盐脱保护。
Synthesis of octalactin lactone and side chain
作者:Merritt B. Andrus、Ankush B. Argade
DOI:10.1016/0040-4039(96)01014-3
日期:1996.7
synthesized in a direct, and efficient manner. Lactone 1 was made using a substrate controlled lactonization reaction using the carbodiimide EDCI and two crotylborane additions were used to access the precursor hydroxyacid. The importance of proper substitution in the hydroxyacid tether is noted for successful medium-ring lactonization. Synthesis of the sidechain vinyl iodide 2 employed an asymmetric allenylboronate