20993-77-5

Upstream product

• 7605-54-1 methyl (1S*,2R*)-2-methylcyclohexanecarboxylate 
• 935-79-5 cis-1,2,3,6-tetrahydrophthalic anhydride 
• 134785-23-2 (+/-)-cis-1-carbomethoxy-2-bromomethyl-4-cyclohexene 
• 133806-73-2 (+/-)-cis-1-carbomethoxy-2-bromomethylcyclohexane 
• 2744-05-0 8-oxabicyclo[4.3.0]non-3-en-9-one 

Relevant academic research and scientific papers

Epimerization of 2- or 4- substituted cyclohexanecarboxylic acids

The present invention relates to a new method for obtaining a purity of about 93% to 100% of the trans form of 2- or 4-substituted cyclohexanecarboxylic acid or reactive derivatives thereof from the cis form or a mixture of the cis and trans forms by a single step, particularly, to a method for obtaining a purity of substantially 100% of the trans form of 4-substituted cyclohexanecarboxylic acid.

Enzymes in organic synthesis 49. Resolutions of racemic monocyclic esters with pig liver esterase

Pig liver esterase (PLE)- catalyzed hydrolyses of the racemic methyl esters of cyclobutane-, cyclohexane-, and cyclohex-4-ene-carboxylic acids bearing cis-2-methyl or cis-2-bromomethyl substituents are highly stereoselective, giving the corresponding acid products of ≥ 97% ee. The stereoselectivity of the enzyme exhibits the expected reversal for such compounds, with the absolute configurations of the cyclobutane and cyclohexame acids being of the opposite absolute configuration type, and cyclopentane substrates such as cis-1-carbomethoxy-2-methylcyclopentane representing the change-over structures and giving products of only 22%ee. This stereoselectivtiy reversal, and the absolute configurations preferred, are as predicted by the recently proposed active site model for the enzyme.