in this paper is reported the stereoselectivesynthesis of all-trans-tetraenes by reductive elimination of 1,8-dibenzoate-2,4,6-trienes with sodium amalgam. The method was applied to the syntheses of 4E, 6E, 8E, 10E-heptatetraene and β—parinaric acid methyl ester.
New transformations of substituted allene sulphoxides
作者:Ian Cutting、Philip J. Parsons
DOI:10.1016/s0040-4039(00)85927-4
日期:1983.1
The preparation and reactions of trimethylsilyl substituted allene sulphoxides are described. Allenes (2) rearrange on warming to give α,β-unsaturated thiol esters.
A novel gold-catalyzed ethynylation of aromatic rings with electron-deficient alkynes via gold catalyzed C-H activation of both C(sp)-H and C(sp(2))-H bonds has been developed. This transformation provides aromatic propiolates difficult to prepare by other methods, highlighting the synthetic potential of gold chemistry.
Kinetic and Dynamic Kinetic Resolution of Secondary Alcohols with Ionic-Surfactant-Coated <i>Burkholderia cepacia</i> Lipase: Substrate Scope and Enantioselectivity
作者:Cheolwoo Kim、Jusuk Lee、Jeonghun Cho、Yeonock Oh、Yoon Kyung Choi、Eunjeong Choi、Jaiwook Park、Mahn-Joo Kim
DOI:10.1021/jo3027627
日期:2013.3.15
Forty-four different secondaryalcohols, which can be classified into several types (II-IX), were tested as the substrates of ionic surfactant-coated Burkholderiacepacialipase (ISCBCL) to see its substrate scope and enantioselectivity in kinetic and dynamickineticresolution (KR and DKR). They include 6 boron-containing alcohols, 24 chiral propargyl alcohols, and 14 diarylmethanols. The results
As an extension of the study on the Hudrlik–Peterson reaction of trans-TMS-epoxy alcohols with lithium acetylides, four cis-TMS-epoxy alcohols possessing different alkyl substituents were subjected to the reaction with TMS-acetylide. The reaction completed in 1 h at 0 °C to afford cis-enynyl alcohols in good yields. The results indicated that cis-TMS-epoxy alcohols had higher reactivity than the trans-isomers