1-Bromo-1-nitroalkenes, reactions with

High syn selectivity can be obtained from the addition of enamines to nitroalkenes. The reaction of 4-(1-cyclohexenyl)morpholine with ( )-l-bromo-4-(2-nitroethenyl)benzene gives, after acid hydrolysis, exclusively the. ryw-adduct, the relative configuration of which was unequivocally... 

A-Containing Heterocycles. Nitroalkenes were reacted with TBDMSCI and DBU to afford A-silyloxyisoazoUdines through the intramolecular olefin cycloadditions of the nitronate intermediates. Only one diastereomer with three new consecutive stereogenic centers was isolated in good to excellent yield. Desi-lylation with TBAF and further spontaneous aerobic oxidation furnished the hydroxymethyl nitro compounds (eq 50). 1-Bromo-nitroalkanes, on the contrary, when treated with TBDMSCI and TEA, underwent the same cycloaddition reaction to produce the nitronates after in situ elimination of TBDMSBr (eq 51). ... 

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