804566-32-3

Upstream product

• 81328-62-3 (2-methylcyclopent-1-enyl)methanol 
• 19009-39-3 N,N-diisopropylcarbamoyl chloride 
• 1122-91-4 4-bromo-benzaldehyde 
• 432555-23-2 (2-methyl-1-cyclopentenyl)methyl N,N-diisopropylcarbamate 

Downstream Products

• 909726-79-0 (1R,2S,4R,5S)-[4-(4-bromophenyl)-5-methyl-2-(1-methylethyl)-3-oxabicyclo[3.3.0]oct-1-yl]methanol 
• 909726-74-5 (1S,2S,4R,5S)-4-(4-bromophenyl)-5-methyl-2-(1-methylethyl)-3-oxabicyclo[3.3.0]octane-1-carboxaldehyde 

Relevant academic research and scientific papers

Enantio- and diastereoselective synthesis of highly substituted acylcyclopropanes from homoaldol products by stereospecific homoallylic cyclization

Highly enantioenriched 4-hydroxy-1-alkenyl N,N-diisopropylcarbamates, easily available by asymmetric homoaldol reaction, cyclize by treatment with sodium hydride to form (1r,2t,3t)-configured 1-acylcyclopropanes with high diastereoselectivity. The decisiv

Synthesis of enantioenriched and diastereomerically pure cis-fused bicyclic α-oxy-substituted γ-lactones via epoxidation of optically active homoaldol products

By applying the (-)-sparteine-mediated asymmetric deprotonation to 1-O-(2-alkylcycloalk-1-enyl)methyl N,N-diisopropylcarbamates, combined with a lithium-titanium exchange followed by addition to achiral aldehydes, enantioenriched homoaldol products 6 were

Stereoselective synthesis of highly substituted bicyclic γ-lactones using homoaldol addition of 1-(1-cycloalkenyl)methyl carbamates

Stereoselective addition of aldehydes 4 to metallated 1-(1-cycloalkenyl) methyl N,N-diisopropylcarbamates 1 gave cyclic homoaldol adducts 6. By applying the (-)-sparteine method, enantiomerically enriched products were obtained. These were oxidatively cyc

Nonracemic, chiral homoenolate reagents derived from (cycloalk-1-enyl)methyl carbamates and evaluation of their configurational stabilities

Several (cycloalk-1-enyl)methyl N,N-diisopropylcarbamates 11 were synthesised by three different methods and their asymmetric deprotonation by butyllithium/(-)-sparteine was investigated. The ratios of epimeric ion pairs 18·4/epi-18·4 were determined by (stereospecific) trimethylsilylation, forming the products 19/ent-19. Lithiated 2-unsubstituted (cyclopent-1-enyl) methyl carbamates, such as 11a or 11h, epimerise rapidly at -78 °C and the thermodynamically controlled ratio is opposite to the kinetically achieved ratio. High configurational stability was found for the 2-methylcycloalk-1-enyl derivatives 11d, 11e and 11j. These turned out to be valuable reagents for enantioselective homoaldol reaction; er values of up to 96:4 could be achieved. X-ray crystal structure analyses with anomalous diffraction, obtained from the heavy atom containing products 22, 23b, 27d, and 27e derived from (2-methylcyclopentenyl)methyl and (2-methyl-cyclohexenyl)methyl reagents, established the (1S) configuration of the major lithium compound. Thus, the kinetically controlled deprotonation of the corresponding allyl carbamates removes the (pro-S) proton. Overall, a simple method for the enantioselective synthesis of cyclic homoaldol adducts from achiral precursors is reported.