Synthesis and proton NMR stereochemical study of 7,8,9‐substituted‐7,8‐dihydro‐4H,9H‐furo[2′,3′,4′:4,4a,5]‐naphth[2,1‐e][1,3]oxazin‐4‐ones

Abstract 7,8,9‐Substituted‐7,8‐dihydro‐4H,9H‐furo[2′,3′,4′:4,4a,5]naphth[2,1‐e][1,3]oxazin‐4‐ones were stereospecifically obtained as a single pair of enantiomers. Their relative trans configuration and the conformation of the dihydro oxazine ring were established by 1H nmr 2D NOESY experiments.