571206-84-3Relevant academic research and scientific papers
Asymmetric Schmidt reaction of hydroxyalkyl azides with ketones
Sahasrabudhe, Kiran,Gracias, Vijaya,Furness, Kelly,Smith, Brenton T.,Katz, Christopher E.,Reddy, D. Srinivasa,Aube, Jeffrey
, p. 7914 - 7922 (2007/10/03)
An asymmetric equivalent of the Schmidt reaction 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 azides, and reaction conditions are varied. Selectivities as high as ca. 98:2 are possible for the synthesis of substituted caprolactams, with up to 1,7-stereoselection involved in the overall process. The fact that either possible migrating carbon is electronically identical provides an unusual opportunity to study a ring-expansion reaction controlled entirely by stereoelectronic factors. The mechanism of the reaction and the source of its stereoselectivity are also discussed.
