would give triphenylphosphine. One-pot transformation of triphenylphosphineoxide to triphenylphosphine was achieved successfully by the treatment of triphenylphosphineoxide with oxalyl chloride and subsequent electroreduction. In a similar manner, some tetra-coordinate triphenylphosphonium species derived from triphenylphosphineoxide were reduced electrochemically to triphenylphosphine in moderate
PROCESSES FOR PREPARING 4-METHYL-5-NONANONE AND 4-METHYL-5-NONANOL
申请人:Shin-Etsu Chemical Co., Ltd.
公开号:US20200199053A1
公开(公告)日:2020-06-25
The present invention provides a process for preparing 4-methyl-5-nonanone of the following formula (3), the process comprising at least a step of subjecting pentanoic anhydride of the following formula (1) and a 2-pentyl nucleophilic reagent of the following general formula (2), in which M represents Li, MgZ
1
, or ZnZ
1
, wherein Z
1
represents a halogen atom or a 2-pentyl group, to a nucleophilic substitution reaction to produce 4-methyl-5-nonanone (3), as well as a process for preparing 4-methyl-5-nonanol of the following formula (7), the process comprising at least steps of preparing 4-methyl-5-nonanone and subjecting the obtained 4-methyl-5-nonanone and a reducing agent to a reduction reaction to produce 4-methyl-5-nonanol (7).
Aza-Amino Acid Scan for Rapid Identification of Secondary Structure Based on the Application of <i>N</i>-Boc-Aza<sup>1</sup>-Dipeptides in Peptide Synthesis
作者:Rosa E. Melendez、William D. Lubell
DOI:10.1021/ja039643f
日期:2004.6.1
validated by the synthesis of six N-Boc-aza(1)-dipeptides and their subsequent introduction into analogues of the C-terminal peptide fragment of the humancalcitoningene-relatedpeptide (hCGRP). By performing an aza-amino acid scan of such antagonist peptides, a set of aza-hCGRP analogues was synthesized to examine the relationship between turn secondary structure and biological activity.
氮杂肽是一种肽类似物,其中一个或多个氨基酸残基的α-碳被氮原子取代,表现出采用β-转角构象的倾向。通过引入氮杂氨基酸残基作为 N-Boc-氮杂 (1)-二肽,现已开发出在固相上无外消旋化的氮杂肽合成通用方案。这种方法已通过六个 N-Boc-aza(1)-二肽的合成及其随后引入人降钙素基因相关肽 (hCGRP) 的 C 端肽片段的类似物得到验证。通过对此类拮抗剂肽进行氮杂-氨基酸扫描,合成了一组氮杂-hCGRP 类似物,以检查转角二级结构与生物活性之间的关系。
The structure of R3PBr2 compounds in the solid state and in solution; geometrical dependence on R, the crystal structures of tetrahedral ionic Et3PBr2 and molecular trigonal bipyramidal (C6F5)3PBr2
作者:Stephen M. Godfrey、Charles A. McAuliffe、Imran Mushtaq、Robin G. Pritchard、Joanne M. Sheffield
DOI:10.1039/a807241h
日期:——
containing iodine or chlorine, [R3PX]X (X = I or Cl) according to 31P-H} NMR studies. In contrast, (C6F5)3PBr2 has a molecularfive-co-ordinate trigonal bipyramidal structure both in CDCl3 solution and in the solid state. The single crystalstructure of this compound has been determined and it represents the only reported R3PBr2 species which contains a five-co-ordinate phosphorus atom. It has D3 symmetry