Trifluoromethylated morpholines condensed with oxetane: Synthesis and transformations

•A simple one-pot, atom and steps economic (PASE) synthesis of trifluoromethylated morpholines condensed with oxazine or oxetane rings has been elaborated.•The assembly of heterocycles from fluorinated α-bromoenones and amino diols is initiated by aza-Michael reaction.•Unexpected isomerization of oxetane-bearing heterocycles into bis-oxazines was found.