The addition of allyltrimethylsilane to cyclic N-acyliminium ions derived from(S)-(+)-mandelic acid and cyclohexyl-based chiral auxiliaries

AUTOR(ES)

D'Oca, Marcelo G. M., Pilli, Ronaldo A., Pardini, Vera L., Curi, Denise, Comninos, Francisco C. M.

FONTE

Journal of the Brazilian Chemical Society

DATA DE PUBLICAÇÃO

2001-08

RESUMO

A adição de aliltrimetilsilano, promovida por TiCl4, a íons N-aciliminios cíclicos de 5- e 6-membros derivados do ácido (S)-(+)-mandélico, (1R,2S)-trans-2-fenil-1-cicloexanol e (1R,2S,5R)-8-fenilmentol ocorreu com baixas a moderadas razões diastereoisoméricas (1:1-6:1) e forneceu as respectivas amidas e carbamatos em bons rendimentos. A melhor diastereosseleção facial foi observada com o uso de (1R,2S,5R)-8-fenilmentol como auxiliar quiral. As amidas e carbamatos 2-substituídos foram convertidos nos alcalóides (S)- e (R)-propil pirrolidina e coniina com eficiente recuperação dos auxiliares quirais.

Documentos Relacionados

• Stereoselective syntheses of (+)- isoretronecanol and (+)-5-epi-tashiromine via addition of chiral titanium (iv) enolates to cyclic n-acyliminium ions
• Studies on the niobium pentachloride-mediated nucleophilic additions to an enantiopure cyclic N-acyliminium ion derived from (S)-malic acid
• Studies on the niobium pentachloride-mediated nucleophilic additions to an enantiopure cyclic N-acyliminium ion derived from (S)-malic acid
• The stereochemistry of the addition of chlorotitanium enolates of N-acyl oxazolidin-2-ones to 5- and 6- membered N-acyliminium ions
• The Stereochemistry of the Addition of Chlorotitanium Enolates of N-Acyl Oxazolidin-2-ones to 5- and 6- Membered N-Acyliminium Ions