Photoisomerization of protonated 5-deuterio-5-methylhex-3-en-2-one. Evidence for a photochemical 1,2 hydride shift

The photoisomerization of protonated 5-deuterio-5-methylhex-3-en-2-one to a protonated dihydrofuran is shown to occur with a specific 1,2 deuterium shift from C-5 to C-4.