19307-62-1

Upstream product

• 32720-57-3 4-(cyclohex-2-en-1-yl)morpholine 
• 3156-70-5 1-Nitropropen 
• 19307-61-0 6-(1-methyl-2-nitroethyl)-1-(4-morpholinyl)cyclohexene 
• 670-80-4 4-cyclohexen-1-ylmorpholine 
• 17082-05-2 (E)-1-nitroprop-1-ene 
• 108-94-1 cyclohexanone 
• 111491-52-2 l,l-4a,5,6,7,8,8a-hexahydro-4-methyl-8a<(trimethylsilyl)oxy>-4H-1,2-benzoxazine-2-oxide 
• 6651-36-1 1-(Trimethylsilyloxy)cyclohexene 
• 111491-52-2 u,l-4a,5,6,7,8,8a-hexahydro-4-methyl-8a<(trimethylsilyl)oxy>-4H-1,2-benzoxazine-2-oxide 

Relevant academic research and scientific papers

SYNTHESIS OF OPTICALLY ACTIVE CONDENSED γ-LACTONES FROM 2-(2-NITROETHYL)CYCLOHEXANOLS. PART II

Baker's yeast shows chemo-, diastereo- and enantioselectivity in the reduction of mixtures of 2-nitroalkylated cyclohexanones.The resulting optically active, nitro-substituted alcohols can be easily transformed into condensed γ-lactones.In that way (+)-is

Enantioselective aldol and Michael additions of achiral enolates in the presence of chiral lithium amides and amines

It is now well established that lithium enolates and analogous derivatives generally exist as complex structures held together by noncovalent bonds ('supramolecules'). In particular, Li enolates aggregate to give dimers, tetramers, and higher oligomers, whose metal centers may be complexed by solvent molecules or chelating ligands. In addition, the anionoid part of the enolates may hydrogen-bond to weak acids such as secondary amines. Furthermore, such supramolecules can be product-forming species in synthetic reactions of Li enolates. This paper describes our observations of the temporary incorporation of chiral amines or chiral lithium amides into achiral lithium enolate aggregates (an interaction which is simply broken during aqueous workup!) to give enantiomerically enriched products. In particular, enantioselective aldol and Michael additions between achiral enolates and achiral aldehydes or achiral nitroolefins have been achieved in the presence of several chiral amines (or their lithium amides) derived from (S)-valine or (R,R)-tartaric acid. Finally, this report demonstrates the potential usefulness in asymmetric synthesis of ortho lithiation directed by chiral α-aminoalkoxides.

Cyclic nitronates from the diastereoselective addition of 1-trimethylsilyloxycyclohexene to nitroolefins. Starting materials for stereoselective Henry reactions and 1,3-dipolar cycloadditions

Induced by a stoichiometric excess of dichloro(diisopropoxy)-titanium, 1-trimethylsilyloxycyclohexene and (E)-nitroolefins (R-CH=CHNO2, R = C6H5, p-C6H4CH3, p-C6H4OCH3, p-C6H4CN, CH3) combine in CH2Cl2 solution at -90 deg C preferentially with relative topicity ul, opposite to the corresponding reaction of enolates or enamines.The primary products are the epimeric bicyclic nitronates 4-6, which can be separated, and which are converted by KF in MeOH to the alkyl or aryl (nitroethyl)-substituted cyclohexanones 1 and 2 (Table 1).Instead of being solvolysed, the cyclic nitronates 4-6 can be used for nitroaldol additions to give the trisubstituted hexahydrobenzopyranols 15-19.Alternatively, 4-6 can be used in 1,3-dipolar cycloadditions with acrylates to furnish the tricyclic compounds 22-31.In either case, products with four asymmetric carbon atoms (not including acetal centres) are produced diastereoselectively.The addition described here is yet another example of an ul combination of trigonal centres induced by Lewis acids, overriding the influence of the configuration of the donor component.