%0 Journal Article
%T The addition of allyltrimethylsilane to cyclic N-acyliminium ions derived from(S)-(+)-mandelic acid and cyclohexyl-based chiral auxiliaries
%A D'Oca Marcelo G. M.
%A Pilli Ronaldo A.
%A Pardini Vera L.
%A Curi Denise
%J Journal of the Brazilian Chemical Society
%D 2001
%I Sociedade Brasileira de Qu¨Şmica, SBQ
%X The TiCl4- promoted addition of allyltrimethylsilane to chiral 5- and 6-membered N-acyliminium ions employing (S)-(+)-mandelic acid, (1R,2S)-trans-2-phenyl-1-cyclohexanol and (1R,2S,5R)-8-phenylmenthol derivatives as chiral auxiliaries occurred with low to moderate diastereoisomeric ratios (1:1-6:1) to afford 2-substituted amides and carbamates in good yields. The best diastereoselection was observed with (1R,2S,5R)-8-phenylmenthol as the chiral auxiliary. The 2-substituted amides and carbamates were converted to the corresponding alkaloids (S)- and (R)-propyl pyrrolidine and coniine with efficient recovery of the chiral auxiliaries.
%K (S)-(+)-Mandelic acid
%K cyclohexyl-based chiral auxiliaries
%K N-acyliminium ions
%K pyrrolidine and piperidine derivatives
%U http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532001000400011