7687-35-6

Upstream product

• 7687-34-5 2-Methyl-cyclobut-1-en-1-carbonsaeuremethylester 
• 186581-53-3 diazomethane 
• 4462-96-8 cis-1,2-cyclobutane dicarboxylic anhydride 
• 7687-33-4 2,3-diaza-bicyclo[3.2.0]hept-2-ene-1-carboxylic acid methyl ester 
• 82442-64-6 (+/-)-cis-3-oxabicyclo<3.2.0>heptan-2-one 
• 42185-61-5 2-methylcyclobutane-1-carboxylic acid 
• 134785-24-3 (+/-)-cis-1-carbomethoxy-2-bromomethyl-cyclobutane 

Downstream Products

• 134877-12-6 (+)-(1S,2R)-1-carbomethoxy-2-methylcyclobutane 
• 301824-29-3 N-[(R)-α-(hydroxymethyl)benzyl]-(1R,2S)-cis-2-methylcyclobutanecarboxamide 
• 301824-30-6 (1S,2R)-2-Methyl-cyclobutanecarboxylic acid ((R)-2-hydroxy-1-phenyl-ethyl)-amide 
• 42185-61-5 cis-2-methylcyclobutanecarboxylic acid 

Relevant academic research and scientific papers

Synthesis, Resolution, and Absolute Stereochemistry of (1R,2S)-(+)-cis-1-Methoxycarbonyl-2-methylcyclobutane

Racemic cfs-1-methoxycarbonyl-2-methylcyclobutane uncontaminated with the trans isomer was prepared efficiently in five steps; the corresponding amides from (R)-(-)-phenylglycinol were separated. An X-ray crystallographic structure determination of the amide from (+)-cis-1-methoxycarbonyl-2-methylcyclobutane showed that it was of (1R,2S) absolute stereochemistry, a revision of configurational assignment.

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.