DIASTEREOSELECTIVE ALKYLATION AND ALDOL REACTIONS MEDIATED BY THE d-MANNITOL-DERIVED OXAZOLIDIN-2-ONE AS A CHIRAL AUXILIARY
摘要:
Chiral N-acylated oxazolidin-2-ones readily available from D-mannitol have been demonstrated to undergo highly diastereoselective alkylation reactions via their lithium imide Z-enolates to afford a-branched products. Evans syn and non-Evans syn aldol products were also selectively obtained using this new auxiliary in high diastereomeric purity by simply changing the stoichiometry of TiCl4 and the nature of the amine base.
DIASTEREOSELECTIVE ALKYLATION AND ALDOL REACTIONS MEDIATED BY THE d-MANNITOL-DERIVED OXAZOLIDIN-2-ONE AS A CHIRAL AUXILIARY
摘要:
Chiral N-acylated oxazolidin-2-ones readily available from D-mannitol have been demonstrated to undergo highly diastereoselective alkylation reactions via their lithium imide Z-enolates to afford a-branched products. Evans syn and non-Evans syn aldol products were also selectively obtained using this new auxiliary in high diastereomeric purity by simply changing the stoichiometry of TiCl4 and the nature of the amine base.