Oxidation of a 4-substituted chiral oxazoline using MCPBA and NO2

Abstract

Oxidation of the chiral oxazoline 1 using 1.6 equivalents of MCPBA gives mainly the corresponding ring-opened nitroso compound 4 isolated as its dimer 5 together with an E/Z mixture of the isomeric oximes 2 and 3. Upon treatment of 1 with an excess of NO 2 the product is the alkyl nitrate 23.

Synthesis of fluorine containing 3-cyano/ethoxycarbonyl-2-ethyl-benzo[b]furans via microwave assisted tandem intramolecular Witting and Claisen rearrangement reactions

“…[3][4][5][6] They were usually synthesized by condensation reactions involving o-hydroxybenzaldehyde or phenolic substrates, 1,[6][7][8][9] Claisen rearrangement reaction of aryl propargylic ethers, [10][11][12] intramolecular Wittig reaction of ohydroxyphenacylidenetriphenylphosphoranes, 13,14 flash vacuum pyrolysis of α-acyl-omethoxybenzylidene-triphenylphosphoranes, 15 tandem intramolecular Wittig and Claisen rearrangement reactions [16][17][18][19] and a host of other methods. 1 …”