Highly Stereoselective and Flexible Synthesis of 6-Alkoxy-5,6-dihydro-4<i>H</i>-1,2-oxazines by Conjugate Addition of Organolithium Compounds to 6<i>H</i>-1,2-Oxazines Followed by Trapping with Electrophiles
作者:Hans-Ulrich Reissig、Monika Buchholz
DOI:10.1055/s-2002-33107
日期:——
additions of reactive organolithium compounds such as phenyllithium, n-butyllithium, tert-butyllithium, and 2-propenyllithium to 6H-1,2-oxazines 1, 24, and 25 followed by trapping of the intermediates with electrophiles gave a variety of highly substituted 6-alkoxy-5,6-dihydro-4H-1,2-oxazines 2-15 and 27-30 generally in very good yields. Most interestingly, this reaction sequence proceeds with high stereocontrol