HCID 3818598, compound → 2H-1-Benzopyran, 2,2-dimethyl-6,7-bis(phenylmethoxy)-

Participants

Reaction Conditions

Reaction Steps

7.8 g (20 millimoles) of 6,7-dibenzyloxy-2,2-dimethyl-4-chromanone are dissolved in 100 ml of a 1:1 mixture of tetrahydrofurane and water, whereupon 5.3 g (30 millimole) of palladium chloride and 8.31 g (220 millimoles) of sodium tetrahydroborate are added. The reaction mixture is stirred at 0° C. for 3 hours, filtered, and the filtrate is extracted three times with 100 ml of ether each. The ether extracts are evaporated, the residue is dissolved in 300 ml of dichloro methane and allowed to stand at 35° C. in the presence of 15 ml of pyridine and 2 g of phosphorous oxychloride for an hour. The reaction mixture is poured into 100 ml of water washed with 5% hydrochloric acid and water. The organic phase is dried and evaporated. The residue is crystallized from methanol. Thus 6 g of the desired compound are obtained, yield 81%. Mp.: 50°-51° C.

Provenance & Evidence