99877-51-7

Upstream product

• 109908-46-5 (2S,3R)-3-(4-Hydroxy-1-methylene-butyl)-2-methyl-cyclopentanone 
• 109833-04-7 (2S,3S)-3-<3'-(dimethyl-t-butylsiloxy)prop-1'(E)-enyl>-2-methylcyclopentanone 
• 75-16-1 methylmagnesium bromide 
• 119987-24-5 (2S,3R)-3-[4-(tert-Butyl-dimethyl-silanyloxy)-1-methylene-butyl]-2-methyl-cyclopentanone 
• 109908-47-6 Toluene-4-sulfonic acid 5-(tert-butyl-dimethyl-silanyloxy)-2-((6S,7S)-6-methyl-1,4-dioxa-spiro[4.4]non-7-yl)-pentyl ester 
• 109908-43-2 5-(tert-Butyl-dimethyl-silanyloxy)-2-((6S,7S)-6-methyl-1,4-dioxa-spiro[4.4]non-7-yl)-pentanal 
• 109908-48-7 5-(tert-Butyl-dimethyl-silanyloxy)-2-((6S,7S)-6-methyl-1,4-dioxa-spiro[4.4]non-7-yl)-pentanenitrile 
• 109908-45-4 tert-Butyl-dimethyl-[4-((6S,7R)-6-methyl-1,4-dioxa-spiro[4.4]non-7-yl)-pent-4-enyloxy]-silane 
• 109908-44-3 5-(tert-Butyl-dimethyl-silanyloxy)-2-((6S,7S)-6-methyl-1,4-dioxa-spiro[4.4]non-7-yl)-pentan-1-ol 
• 109908-42-1 ((6S,7S)-6-Methyl-1,4-dioxa-spiro[4.4]non-7-yl)-acetonitrile 
• 109908-40-9 (2S,3S)-2-methyl-3(bromomethyl)cyclopentanone 
• 109908-41-0 (6S,7R)-7-Bromomethyl-6-methyl-1,4-dioxa-spiro[4.4]nonane 
• 122058-47-3 (4R,1'S,2'S,3'R)-4-(3'-hydroxy-2',3'-dimethylcyclopentyl)-5-(methanesulfonyloxy)pentyl pivalate 
• 122091-65-0 2,2-Dimethyl-propionic acid (S)-4-((1S,2S,3R)-3-hydroxy-2,3-dimethyl-cyclopentyl)-hex-5-enyl ester 

Downstream Products

• 144426-65-3 (R)-3,3,3-Trifluoro-2-methoxy-2-phenyl-propionic acid 4-((1R,2S,3R)-3-hydroxy-2,3-dimethyl-cyclopentyl)-pent-4-enyl ester 
• 121979-32-6 chokol F 

Relevant academic research and scientific papers

Enantioselective Route to (-)-Chokol A

Stereoselective introduction of a methyl group to (3R)-2-methylcyclopentanone (2), followed by orthoester Claisen rearrangement provided the methyl ester (6) leading to (-)-chokol A (4).

Total synthesis of (-)-chokol A by an asymmetric domino Michael addition-Dieckmann cyclization

A convergent and asymmetric total synthesis of (-)-chokol A was accomplished in six steps starting from the α,β-unsaturated ester (E)-9 in an overall yield of 27% with an enantiomeric excess of 95%. The key step of this synthesis is the asymmetric tandem conjugate addition-Dieckmann cyclization of the higher-order cuprate 8 derived from vinyl bromide 7 with the α,β-unsaturated ester (E)-9. Georg Thieme Verlag Stuttgart.

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).

Efficient Chemical Conversion of (+/-)-Chokol G to (+/-)-Chokols A, B, C, F, and K, Chokolic Acid B, and Chokolal A

Fungitoxic sesquiterpenoid chokols A, B, C, F, and K, chokolic acid B, and chokolal A were synthesized from chokol G by modifying the side chain.

Stereoselective Synthesis of Steroids and Related Compounds, V. Synthesis of (+/-)-Chokol A by a Tandem Michael-Addition/Dieckmann Cyclization

A total synthesis of (+/-)-chokol A (rac-12) was accomplished in five steps by starting from the α,β-unsaturated ester (E)-2 in an overall yield of 24percent.The key step of this synthesis is the tandem conjugate addition/Dieckmann cyclization of the cupr

Highly Enantioselective Synthesis of (-)-Chokol A

Stereoselective introduction of a methyl group into the (3S)-2-methylcyclopentanone 3, followed by Claisen rearrangement of the vinyl ether 10 derived from the allyl alcohol 7 provided separable methyl esters 6a and 6b.Reduction of 6a and subsequent homol

A CONCISE SYNTHESIS OF (+/-) CHOKOL A

The fungitoxic sesquiterpene chokol A was synthesized via a six step sequence which used the addition reaction of a functionalised cuprate reagent to cyclopentenone as the key step.

Homochiral Ketals in Organic Synthesis. Enantioselective Synthesis and Absolute Configuration of (-)-Chokol A.

An enantioselective synthesis of (-)-chokol A from 2-methyl-2-cyclopenten-1-one is described.

TOTAL SYNTHESIS OF (+/-)CHOKOL-A VIA AN INTRAMOLECULAR TYPE-I-MAGNESIUM ENE REACTION.

The sesquiterpene (+/-)chokol-A (1) was synthesized in a diastereoselective manner starting from 1-hexen-5-one-trisylhydrazone (5).The key step 7 -> 8 involves the regio- and stereo-selective magnesium-ene reaction 4 -> 3.