172374-01-5

Upstream product

• 64-17-5 ethanol 
• 172374-00-4 (1R,2R,3S,4S)-<3--2-bornyl>-(1S,5R)-5-(5-tert-butyl-diphenyl-silyloxy-1-penten-2-yl)-2-oxo-cyclopentanecarboxylate 
• 64180-78-5 4-bromopent-4-en-1-ol 
• 58479-61-1 tert-butylchlorodiphenylsilane 
• 172490-96-9 (1R,2R,3S,4S)-<3--2-bornyl>-2-oxo-cyclopentene-carboxylate 
• 161551-45-7 ((4-bromopent-4-en-1-yl)oxy)(tert-butyl)diphenylsilane 

Downstream Products

• 172490-98-1 (1R,2S,3R)-3-(5-tert-butyldiphenylsilyloxy-1-penten-2-yl)-1,2-dimethyl-cyclopentanol 
• 172490-97-0 (2S,3R)-3-(5-tert-butyldiphenylsilyloxy-1-penten-2-yl)-2-methyl-cyclopentanone 
• 99877-51-7 4-(3-hydroxy-2,3-dimethyl-cyclopentyl)-pent-4-ene-1-ol 
• 172374-02-6 ethyl (1R,5S)-5-(5-tert-butyldiphenyl-silyloxy-1-penten-2-yl)-1-methyl-2-oxo-cyclopentanecarboxylate 

Relevant academic research and scientific papers

A Short Synthesis of (-)-Chokol A

(-)-Chokol A (10) was prepared in six steps (22 percent overall yield) via conjugate addition of a higher order cyanocuprate to the chiral 2-oxo-cyclopentenecarboxylate 2n.After deprotection by transesterification the enantiomerically pure β-ketoester 5 was obtained which was transformed by α-methylation and subsequent decarbethoxylation to the cyclopentanone derivative 8.Addition of methylcerium dichloride resulted in a mixture of 9a, 9b and 9c (78:16:6), from which the main diastereomer 9a was separated by MPLC.Finally desilylation of 9a achieved (-)-chokol A (10).