Boron trifluoride etherate → 2,3,4,5-Tetrahydro-1-benzoxepin-4-one

Participants

Reaction Conditions

Reaction Steps

To a solution of 4-chromanone (9.54 g, 64.3 mmol) in diethyl ether at 0° C. was slowly added boron trifluoride diethyl etherate (16.3 ml, 128.6 mmol), followed by the dropwise addition of 2M TMSCHN2 in diethyl ether. The mixture was allowed to stir for 1 hour at 0° C. before diluting with sat. sodium bicarbonate solution and diethyl ether. The organic phase was dried, concentrated, and purified on silica to give 2,3-dihydro-5H-benzo[b]oxepin-4-one.

Provenance & Evidence