53528-32-8Relevant articles and documents
Cobalt-Catalyzed Reductive Dimethylcyclopropanation of 1,3-Dienes
Werth, Jacob,Uyeda, Christopher
, p. 13902 - 13906 (2018/10/02)
Dimethylcyclopropanes are valuable synthetic targets that are challenging to access in high yield using Zn carbenoid reagents. Herein, we describe a cobalt-catalyzed variant of the Simmons–Smith reaction that enables the efficient dimethylcyclopropanation of 1,3-dienes using a Me2CCl2/Zn reagent mixture. The reactions proceed with high regioselectivity based on the substitution pattern of the 1,3-diene. The products are vinylcyclopropanes, which serve as substrates for transition-metal-catalyzed ring-opening reactions, including 1,3-rearrangement and [5+2] cycloaddition. Preliminary studies indicate that moderately activated monoalkenes are also amenable to dimethylcyclopropanation under the conditions of cobalt catalysis.
Process for producing cyclopropanecarboxylates
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, (2008/06/13)
There is disclosed a process process for producing a cyclopropanecarboxylate of formula (1): 1which process comprises reacting cyclopropanecarboxylic acid of formula (2): 2with a monohydroxy compound of formula (3): R6OH??(3),in the presence of a catalyst compound comprising an element of to Group 4 of the Periodic Table of Elements.
Three-Bond 13C-1H Coupling Constants for Chrysanthemic Acid and Phenothrin Metabolites: Detection by Two-Dimensional Long-Range 13C-1H J-Resolution Spectroscopy
Ando, Tetsu,Koseki, Nozomu,Toia, Robert F.,Casida, John E.
, p. 90 - 93 (2007/10/02)
Two-dimensional long-range 13C-1H J-resolution spectroscopy (LRCJR) was used to measure three-bond 13C-1H coupling constants 3J(C,H)> for trans- and cis-chrysanthemic acid, methyl trans-pyrethrate and some microsomal metabolites of the trans-chrysanthemate biophenothrin.The carbon of the methyl cis-disposed to an attached proton shows a larger 3J(C,H) value than does the trans-carbon for the dimethyl-substituted cyclopropane and epoxide rings.The reverse situation applies for the analogous dimethyl vinyl grouping.The 3J(C,H) values are not altered on conversion of one of the olefinic geminal methyl groups to a hydroxymethyl or methoxycarbonyl functionality, but increase on transformation to an aldehyde.These 3J(C,H) values are in agreement with previous results from long-range C-H COSY experiments, and provide a useful method for determining the stereochemistry of chrysanthemic acid derivatives. KEY WORDS: Long-range 13C-1H coupling constants, Long-range 13C-1H J-resolution spectroscopy, Chrysanthemic acid, Pyrethroid, 2D NMR