potassium salt of nitroacetaldehyde 、 苯甲酰氯 以
硝基甲烷 为溶剂,
反应 2.25h,
以85%的产率得到benzoic acid 2-nitrovinyl ester
参考文献:
名称:
The Tandem Cycloaddition Chemistry of Nitroalkenes. A Novel Synthesis of (-)-Hastanecine
摘要:
A short and efficient asymmetric synthesis of the pyrrolizidine necine base (-)-hastanecine is described. The key reaction in the synthesis is a sequential inter [4+2]/inter[3+2] cycloaddition. The Lewis acid promoted [4+2] cycloaddition between 2-acyloxy nitroalkene 16 and chiral vinyl ether 17 afforded a nitronate which underwent facile [3+2] cycloaddition with dimethyl maleate. The resulting nitroso acetal 19 had all the required stereocenters for (-)-hastanecine. The critical unmasking of the nitroso acetal 19 employed a hydrogenolytic cleavage to give the 1-azabicyclo-[3.3.0]octane skeleton of (-)-hastanecine.
Tandem Cycloaddition Chemistry of Nitroalkenes: Preparative and Theoretical Studies on the Stereochemical Course of [3 + 2] Cycloaddition of Cyclic Nitronates
作者:Scott E. Denmark、Mark Seierstad、B. Herbert
DOI:10.1021/jo9818374
日期:1999.2.1
Intermolecular [3 + 2] cycloadditions between two cyclic nitronates and a series of dipolarophiles are examined. High facial selectivity is observed in all cases and is analyzed with the aid of ab initio transition structure calculations. Monosubstituted dipolarophiles reacted with exclusive regiocontrol. Disubstituted dipolarophiles reacted with varying degrees of regiocontrol, which was dependent
Tandem Inter [4 + 2]/Intra [3 + 2] Cycloadditions of Nitroalkenes. Asymmetric Synthesis of Highly Functionalized Aminocyclopentanes Using the Bridged Mode (β-Tether) Process
作者:Scott E. Denmark、Julie A. Dixon
DOI:10.1021/jo9802170
日期:1998.9.1
An asymmetric, tandem inter [4 + 2]/intra [3 + 2] bridged mode (beta-tether) cycloaddition of nitroalkenes has been developed. This new sequence involves the Lewis acid-promoted [4 + 2] cycloaddition of nitro olefins with enantiopure 1-alkoxy-1,4-dienes. The resulting nitronates, bearing a C(5) tethered dipolarophile, undergo thermal, intramolecular [3 + 2] cycloaddition to afford stable tricyclic
[formula: see text] The first synthesis of (+)-casuarine, a pentahydroxy pyrrolizidine alkaloid, is described. The key bond-forming events occur in a tandem [4 + 2]/[3 + 2] nitroalkenecycloaddition involving nitroalkene 6, chiral vinyl ether 7b, and vinyl silane 4. This process also creates five of the six stereocenters present in this potent glycosidase inhibitor. Completion of the synthesis required only
The tandem inter [4+2]/intra [3+2] cycloaddition of nitroalkenes in the bridged mode was applied to the stereoselective synthesis of β-D-4-amino-2,4-dideoxycarbagulose, a representative aminocarbasugar. The synthesis required only five steps from known materials and delivered the protected aminocarbasugar (−)-20 in excellent yield (see Scheme 9). The success of the synthetic sequence relies on 1) the
COMPOSITIONS AND METHODS FOR JAMM PROTEIN INHIBITION
申请人:Cleave Biosciences, Inc.
公开号:US20140235548A1
公开(公告)日:2014-08-21
Compounds, pharmaceutical compositions, and methods of using such compounds to treat or prevent diseases or disorders associated with or mediated by JAMM proteins are disclosed. The compounds and compositions inhibit the enzymatic activity of a JAMM domain, including the JAMM domain of the CSN5 subunit of the COP9-signalsome (CSN), the JAMM domain of the Rpn11/Poh1/Psmd14 subunit of the 26S proteasome, the JAMM domain of AMSH, the JAMM domain of AMSH-LP, the JAMM domain of BRCC36, among other JAMM domains.