676345-39-4

Upstream product

• 104321-94-0 (Diethoxy-phosphoryl)-acetic acid (1R,2R,3S,4S)-3-[benzenesulfonyl-(3,5-dimethyl-phenyl)-amino]-1,7,7-trimethyl-bicyclo[2.2.1]hept-2-yl ester 
• 87360-02-9 N-(3,5-Dimethyl-phenyl)-N-((1S,2S,3R,4R)-3-hydroxy-4,7,7-trimethyl-bicyclo[2.2.1]hept-2-yl)-benzenesulfonamide 
• 917-57-7 vinyllithium 
• 1826-67-1 vinyl magnesium bromide 
• 172490-96-9 (1R,2R,3S,4S)-<3--2-bornyl>-2-oxo-cyclopentene-carboxylate 
• 611-10-9 2-ethoxycarbonyl-1-cyclopentanone 

Relevant academic research and scientific papers

3-Substituted and 2,3-Disubstituted Cyclopentanones via an Asymmetric Tandem 1,4-Addition/Dieckmann Cyclization

A new stereoselective method for the synthesis of 3-substituted and 2,3-disubstituted cyclopentanones is described. The key step is the 1, 4-addition of a cuprate to a chilar Michael-acceptor derived from (-)-8-phenylmenthol or the Helmchen auxiliary followed by Dieckmann cyclization of the obtained chiral enolates. The resultant 2,3-cyclopentanones can be transformed after methanolysis and demethoxycarbonylation to the related 3-substituted cyclopentanones.

Enatiomerically pure 5-substituted 2-oxo-cyclopentanecarboxylates by conjugate addition of cuprates to asymmetry shielded 2-oxo-cyclopentenecarboxylates

Asymmetric shielded 2-oxo-cyclopentenecarboxylates 6n and 6x were prepared by transesterification of 2-oxo-cyclopentanecarboxylate 2 with camphor derived concave alcohols 1n and 1x and by subsequent introduction of a double bond via phenylselenides. Diastereoselective conjugate addition of equimolar amounts of mixed cuprates at -78°C and deprotection by ethanolysis gave enantiomerically pure 5-substituted 2-oxo-cyclopentanecarboxylates 13-18 and ent-13-18, valuable as chiral building blocks in natural product synthesis.

EPC synthesis of 5-substituted 2-oxo-cyclopentanecarboxylates via conjugate addition of cuprates to asymmetric shielded 2-oxo-cyclopentenecarboxylates

Asymmetric shielded 2-oxo-cyclopentenecarboxylates 6n and 6x were prepared by trans-esterification of 2-oxo-cyclopentanecarboxylate 2 with camphor derived concave alcohols 1n and 1x and by subsequent introduction of a double bond via phenylselenides. Dias