Triethyl phosphite → 7,8-dihydro-6,6-dimethyl-7,8-epoxy-6H-pyrano[2,3-f]benz-2,1,3-oxadiazole

Participants

Reaction Steps

To a mixture of 1.00 g (4.27 m mol) of 7,8-dihydro-6,6-dimethyl-7,8-epoxy-6H-pyrano [2,3-f] benzo-2,1,3-oxadiazole 3-oxide and 6 ml of benzene was added dropwise 0.80 ml (4.70 m mol) of triethyl phosphite over 15 minutes at 60° C. under stirring. Then, the mixture was stirred for three hours. After the solvent was removed under the reduced pressure, the residue was subjected to a silica gel column chromatography using a developing solvent of ethyl acetate-hexane (1:1 (v/v)) to obtain 0.82 g of the intended compound (yield: 88%). A part of the obtained compound was recrystallized from hexane to obtain yellow crystals (m.p.: 97° to 99° C.).

Provenance & Evidence