140836-91-5

Upstream product

• 114364-69-1 ethyl <(3R,4S)-3,4-isopropylidenedioxytetrahydrofuran-2-yl>acetate 
• 213767-09-0 2,3-O-isopropylidene-L-erythrofuranose 
• 95517-36-5 ethyl 3-((4R,5R)-5-formyl-2,2-dimethyl-1,3-dioxolan-4-yl)propanoate 
• 140836-88-0 ethyl 3-((4R,5S)-2,2-dimethyl-5-vinyl-1,3-dioxolan-4-yl)propanoate 
• 124575-39-9 ethyl 3-((4R,5S)-5-(hydroxymethyl)-2,2-dimethyl-1,3-dioxolan-4-yl)propanoate 
• 114364-60-2 ethyl 3-((4R,5S)-5-(hydroxymethyl)-2,2-dimethyl-1,3-dioxolan-4-yl)acrylate 
• 5707-04-0 Phenylselenyl chloride 
• 140837-09-8 (+)-(4R,5S)-4,5-isopropylidenedioxyhept-6-enoic acid 

Relevant academic research and scientific papers

Acyl Radical Cyclization in Synthesis. Part 4. Tandem Processes: The 7-endo/5-exo Serial Cyclization Approach to Enantiomerically Pure Bicyclodecan-2-ones

Two diastereoisomeric phenylselenoesters of 4,5-dihydroxyhept-6-enoic acid were prepared as their acetonide derivatives from the chiral pool.On treatment with tributyltin hydride and azoisobutyronitrile the erythro isomer cyclized to give meso-4,5-dihydroxycycloheptanone, as its acetonide, in moderate yield whereas under the same conditions the threo-isomer gave a much lower yield of the corresponding C2-symmetric ketone.In the erythro-series an alkyl group at C-7 of the heptenoyl system was found to retard significantly the direct endo-mode cyclisation; however, the cycloheptanone could still be obtained by a rearrangement when the tin hydride concentration was kept to a minimum.A tandem 7-endo/5-exo cyclization system was then constructed and tested, resulting in the formation of all four possible diastereoisomeric biyclodecanones.Further model studies were conducted on the effect of alkyl and alkoxy substituents at C-5 of the heptenoyl radical system on the mode of cyclisation.Alkyl substituents exert a steric effect whilst alkoxy substituents also have a stereoelectronic effect.

An acyl radical initiated tandem 7-endo/5-exo radical cyclization approach to enantiomerically pure bicyclo[5.3.0]decan-2-ones

The preparation of acetonide derivatives of erythro and threo 4,5-dihydroxyhept-6-enoic acids from the chiral pool is described. The phenylseleno esters derived from these acids undergo cyclization with tributyltin hydride to give mixtures of cyclohexanones and cycloheptanones. The inclusion of the appropriate four carbon side chain at C-7 leads, via a tandem radical cyclization process, to the title compounds in moderate yield.