Facile access to [1,2]-oxazine derivatives via annulations of aminoxy-tethered 1,7-enynes

Abstract

An efficient approach for the highly diastereoselective construction of functionalized cyclopenta[d][1,2]oxazines via sequential oxyamination and Pauson–Khand reaction of readily accessible propargylic alcohols has been developed. Furthermore, the ring closing metathesis of these N–O linked 1,7-enynes afforded vinylated-[1,2]oxazines in good yields. The reduction of the N–O bond of the obtained cyclopenta[d][1,2]oxazine is accomplished to access cyclopentenone-based amino alcohols.