Hydrogen Bromide → CHROMAN-8-OL

Participants

Reaction Steps

The compound obtained in Step C (1 g; 6.09 mmol) is dissolved in glacial acetic acid (10.2 ml) and then hydrobromic acid (48% solution in water) (3.7 eq.; 47 mmol; 2.54 ml) is added dropwise. The phenol is fully deprotected after 5 hours' reflux. After removal of the solvent under reduced pressure, the dry residue is taken up in aqueous medium and then neutralised with a saturated sodium hydrogen carbonate solution to a pH of 8. Extraction with ethyl acetate yields an orange oil after drying and concentration. After purification of the latter over a silica column. AcOEt/PE (3:7), the oil is yellow in colour.

Provenance & Evidence