6568-33-8

Upstream product

• 4308-14-9 cis-trans-1,8-Cyclotetradecadien 
• 625123-22-0 3-vinylcyclotridecanone 
• 628-92-2 Cycloheptene 
• 93111-01-4 (triphenylphosphonio)-5-(lithiooxo)pentylide 
• 75426-30-1 (Z)-5-cyclotetradecenone 
• 114157-21-0 (Z)-14-iodo-1,7-tetradecadien-3-one 
• 114157-34-5 (Z)-Cyclotetradec-5-enol 
• 114157-41-4 14-bromo-1,7-tetradecadien-3-one 
• 114157-45-8 (Z)-14-Bromo-tetradeca-1,7-dien-3-ol 
• 114157-47-0 (Z)-12-Bromo-dodec-5-enal 
• 114157-20-9 12-bromo-5-dodecenol 
• 54005-84-4 7-bromoheptanal 
• 114157-35-6 (Z)-6-Bromo-cyclotetradecene 
• 63521-77-7 1,14-tetradodecanedial 

Relevant academic research and scientific papers

Diradical-promoted two-carbon ring-expansion reactions by thermal isomerization: Synthesis of functionalized macrocyclic ketones

A new method for the smooth and highly efficient preparation of functionalized macrocyclic ketones has been developed. Pyrolysis of medium- and large-ring 3-vinylcycloalkanones by dynamic gas-phase thermo-isomerization (DGPTI) at 600-630° yielded, under insertion of a previously attached vinyl side chain by means of a 1,3-C shift, the corresponding γ,δ- unsaturated cycloalkanones. The yield of the two-carbon ring-expanded ketones greatly depended on the relative ring strains of substrate and product (5-87%, cf. Table 5). The formation of minor amounts of one-carbon ring-expanded cycloalkenes (10%) can be ascribed to a subsequent decarbonylation step. A reaction mechanism involving initial cleavage of the weakest single bond in the molecule has been established (cf. Scheme 6). Recombination within the generated diradical intermediate in terminal vinylogous position led to the observed products, while reclosure gave recovered starting material. Substituents on the vinyl moiety were transferred locospecifically into the ring-expanded products. An isopropenyl group did not significantly affect the isomerization process, whereas substrates bearing a prop-1-enyl group in β-position enabled competing intramolecular H-abstraction reactions, leading to acyclic dienones (cf. Schemes 9-11). DGPTI of the 13-membered analogue directly yielded 4-muscenone, which, upon hydrogenation, led to the valuable musk odorant (±)-muscone. Increasing the steric hindrance on the vinyl moiety gave rise to diminishing amounts of the desired γ,δ-unsaturated cycloalkanones. This novel two-carbon ring-expansion protocol was also successfully applied to 3-ethynylcycloalkanones, giving rise to the corresponding ring-expanded cyclic allenes (cf. Scheme 13).

A Simple Synthesis of Macrocyclic Hydrocarbons by Metathesis of Cycloolefins

Metathesis of cycloolefins normally leads to unsaturated polymers.Using rheniumheptoxide on alumina, activated by tintetramethyl and working in dilution via soxhlet-similiar circulation system the metathesis reaction was directed to macrocyclic dienes, which are the dimers of the initial cyclolefins.Starting with C7-, C9- and C10-cycloolefins symmetric macrocyclic C14-, C18- and C20-dienes are obtained in yields of 58-74percent.The metathetic dimerization of cyclooctene leads to 1,9-cyclohexadecadiene in a yield of 30percent.By hydrogenation at room temperature and normalhydrogen-pressure all cyclodienes were converted quantitatively to cycloalkenes (catalyst: potassium on alumina) or to cycloalkanes (catalyst: palladium on carbon).