Indução assimétrica 1,5-Anti na adição de enolatos de boro de metilcetonas beta-oxigenadas a aldeídos
High levels of substrate-based 1,5-stereoinduction are obtained in the boron-mediated aldol reactions of beta-oxygenated methyl ketones with achiral and chiral aldehydes. Remote induction from the boron enolates gives the 1,5-anti adducts, with the enolate pi-facial selectivity critically dependent upon the nature of the beta-alkoxy protecting group. This 1,5-anti aldol methodology has been strategically employed in the total synthesis of several natural products. At present, the origin of the high level of 1,5-anti induction obtained with the boron enolates is unclear, although a model based on a hydrogen bonding between the alkoxy oxygen and the formyl hydrogen has been recently proposed.
Saved in:
| Main Authors: | , |
|---|---|
| Format: | Digital revista |
| Language: | Portuguese |
| Published: |
Sociedade Brasileira de Química
2007
|
| Online Access: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40422007000800036 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|