Asymmetric Schmidt Reaction of Hydroxyalkyl Azides with Ketones
作者:Kiran Sahasrabudhe、Vijaya Gracias、Kelly Furness、Brenton T. Smith、Christopher E. Katz、D. Srinivasa Reddy、Jeffrey Aubé
DOI:10.1021/ja0348896
日期:2003.7.1
asymmetric equivalent of the Schmidtreaction permits stereocontrol in ring expansions of symmetrical cyclohexanones. The procedure involves the reaction of chiral 1,2- and 1,3-hydroxyalkyl azides with ketones under acid catalysis; the initial reaction affords an iminium ether that can be subsequently opened with base. A systematic study of this reaction is reported, in which ketone substrates, chiral hydroxyalkyl
1,7-Asymmetric Induction in a Nitrogen Ring Expansion Process Facilitated by in Situ Tethering
作者:Kelly Furness、Jeffrey Aubé
DOI:10.1021/ol990685b
日期:1999.8.1
[GRAPHICS]There are only a few methods for the asymmetric ring expansion of prochiral ketones. Symmetrically substituted cyclohexanones can be converted to the corresponding ring expanded caprolactam with excellent 1,7 diastereoselectivity (greater than or equal to 93% ds) and yields (greater than or equal to 86%), using a chiral hydroxy azide-mediated Schmidt reaction.
Synthetic aspects of an asymmetric nitrogen-insertion process: preparation of chiral, non-racemic caprolactams and valerolactams. Total synthesis of (-)-alloyohimbane