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ln arder to synthesize a new chiral phase transfer catalyst we envisaged a synthetic route starting from pyridinium salts bearing a chiral N-substituted derived from cx-aminoacids or a.-aminoalcohols. As a first step 2,4,6-trimethyl and 2,4,6-triphenyl substituted pyridinium salts were submitted to the reduction with NaB~. ln the first case 1,2,5,6-tetrahydropyridines were obtained as main products . For the 2,4,6-triphenyl devivatives the reduction produts were 1,2-dihydropyridines. The latter compom1ds were reacted with two different dienophiles yielding, in each case, two diasteromeric adducts in equal proportions. Under N-alkylation conditions, these isoquinuclidenes were decomposed into the retro aza Diels-Alder produts . ln arder to circunvent such drawback, the Diels-Alder adducts were catalytically hydrogenated. These saturated adducts could not be N-alkylated due to the occurance of Ho:finann elin1ination on the resulting salts. INTRODUÇÃO E OBJETIVOS A catálise de transferência de fase assimétrica tem sido utilizada desde a década de 70 como uma alternativa às sínteses clássicas . Dentre os catalisadores de transferência de fase mais utilizados estão os sais derivados da efedrina (1) e de alcalóides da cinchona (2 e 3) (Figura 1)1 .

Estudo da aplicação de adutos de Diels-Alder como intermediário de novos catalisadores de transferência de fase assimétrica