45889-43-8Relevant academic research and scientific papers
Hydrolysis of iminium ethers derived from the reaction of ketones with hydroxy azides: Synthesis of macrocyclic lactams and lactones
Forsee, Jennifer E.,Aube, Jeffrey
, p. 4381 - 4385 (2007/10/03)
The hydrolysis of iminium ether intermediates formed by a nitrogen insertion sequence involving azido alcohols 1 or 2 and ketones was investigated. Ketones containing 6-12-membered rings were surveyed and shown to provide lactams and lactones in good to excellent overall yield. Reactions employing acetone or 5-nonanone gave similar results, generating analogous amides and esters. The relative amounts of lactone vs lactam produced in a given reaction were found to depend on the structures of the reactants and the pH of the basic media used to hydrolyze the iminium ethers. A mechanism accounting for the formation of each product is discussed in terms of ring strain and the protonation state of ortho ester aminal intermediates.
Ring expansion by in situ tethering of hydroxy azides to ketones: The boyer reaction
Gracias, Vijaya,Frank, Kristine E.,Milligan, Gregory L.,Aube, Jeffrey
, p. 16241 - 16252 (2007/10/03)
Although alkyl azides can react with ketones to form ring- expanded lactams, the reaction suffers from poor generality and the need to use powerful Lewis acid promotion. The reactions of 1,2- and 1,3-hydroxyalkyl azides with ketones yield N-hydroxyalkyl lactams in high yields under the action of protic or Lewis acids such as BF3·OEt2. The reaction appears to succeed due to the initial formation of a hemiketal, which then renders the attack of azide on an oxonium ion intramolecular. The scope of this reaction vis a vis ketone and hydroxyalkyl azide structure is discussed.
