Water → 7-Methoxy-4-methyl-2H-1-benzopyran

Participants

Reaction Steps

The carbinol of step (a) (73.3 g) was stirred with phosphorus oxychloride (19.3 g; 11.6 ml) in dry pyridine (380 ml) for 20 hours under nitrogen. The reaction mixture was poured into water, extracted with ether and the ethereal extracts were washed with dilute acid, then sodium bicarbonate solution, then water and dried. Evaporation of the solvent left 58 g of residue (87.2%). MS evidence was correct for the required compound. NMR suggested that the product was in fact a mixture of isomeric alkenes.

Provenance & Evidence