Synthesis and reactions of 3-halomethyl-substituted oxazine N-oxides
作者:Andrey A. Mikhaylov、Alexander D. Dilman、Roman A. Kunetsky、Yulia A. Khomutova、Marina I. Struchkova、Alexander A. Korlyukov、Sema L. Ioffe、Vladimir A. Tartakovsky
DOI:10.1016/j.tetlet.2009.12.066
日期:2010.2
A series of 3-halomethyl-5,6-dihydro-1,2-oxazine N-oxides (halogen = Cl, Br, I) is prepared from 4-phenyl-3,6,6-trimethyl-5,6-dihydro-4H-oxazine N-oxide by means of a silylation/halogenation sequence. The obtained halogenated N-oxides undergo reactions typical of cyclic six-membered nitronates including 1,3-dipolar cycloaddition, addition of nucleophiles, and substitution of the halogen by C-, S-, and N-nucleophiles. (C) 2009 Elsevier Ltd. All rights reserved.
Five-Membered Cyclic Nitronates in C-C Coupling with 1-(<i>tert</i>-Butyldimethylsilyloxy)-1-methoxyethylene
作者:Vladimir O. Smirnov、Alexander S. Sidorenkov、Yulia A. Khomutova、Sema L. Ioffe、Vladimir A. Tartakovsky
DOI:10.1002/ejoc.200900172
日期:2009.6
Five-memberedcyclicnitronates 3 undergo TBSOTf-catalysed C–Ccoupling reactions with silyl ketene acetal 4 to give good to excellent yields of 3,3-disubstituted N-(OTBS)-isoxazolidines 5, which could not be obtained by previously known procedures. The problems of diastereoselectivity of the C–Ccoupling reactions are discussed. The transformations of the nitroso acetals 5 upon action of AcFOH/methanol