Asymmetric allylation of aldehydes using tiglyltitanocenes attached to a carbohydrate
摘要:
eta(3)-Tiglyltitanium complexes bearing alpha- or beta-glucopyranosyl auxiliaries were synthesized starting from the corresponding C1-dienopyranosides. These complexes were reacted with propanal and (-)-myrtenal to afford 4-hydroxy-3-methylvinylglycoside derivatives. In several cases, high diastereofacial selectivities were obtained. Thus, the reaction employing (-)-myrtenal and beta-glucopyranosyl tiglyltitanium complex led to the unique (d.s.greater than or equal to 98%) 3R/4R-configurated compound bearing the sugar and pinenyl fragments, which can be considered as a promising new chiron. (C) 1997 Elsevier Science Ltd.
Asymmetric allylation of aldehydes using tiglyltitanocenes attached to a carbohydrate
摘要:
eta(3)-Tiglyltitanium complexes bearing alpha- or beta-glucopyranosyl auxiliaries were synthesized starting from the corresponding C1-dienopyranosides. These complexes were reacted with propanal and (-)-myrtenal to afford 4-hydroxy-3-methylvinylglycoside derivatives. In several cases, high diastereofacial selectivities were obtained. Thus, the reaction employing (-)-myrtenal and beta-glucopyranosyl tiglyltitanium complex led to the unique (d.s.greater than or equal to 98%) 3R/4R-configurated compound bearing the sugar and pinenyl fragments, which can be considered as a promising new chiron. (C) 1997 Elsevier Science Ltd.
Asymmetric allylation of aldehydes using tiglyltitanocenes attached to a carbohydrate
作者:Didier Felix、Jan Szymoniak、Claude Moïse
DOI:10.1016/s0040-4020(97)10029-1
日期:1997.11
eta(3)-Tiglyltitanium complexes bearing alpha- or beta-glucopyranosyl auxiliaries were synthesized starting from the corresponding C1-dienopyranosides. These complexes were reacted with propanal and (-)-myrtenal to afford 4-hydroxy-3-methylvinylglycoside derivatives. In several cases, high diastereofacial selectivities were obtained. Thus, the reaction employing (-)-myrtenal and beta-glucopyranosyl tiglyltitanium complex led to the unique (d.s.greater than or equal to 98%) 3R/4R-configurated compound bearing the sugar and pinenyl fragments, which can be considered as a promising new chiron. (C) 1997 Elsevier Science Ltd.