Hydrochloric Acid → Gitoxigenin

Participants

Reaction Steps

A suspension of 4.7 grams of gitoxin in 300 ml of ethanol containing 4.7 ml of conc. hydrochloric acid was stirred for three days, warmed gently for ten hours then stirred for another day at room temperature. The acidic solution was neutralized by the addition of solid sodium carbonate, then filtered to yield a clear colorless solution. The solvent was removed on a rotary evaporator and the residue was mulled in water to remove carbohydrate hydrolysis products. The residue was extracted into a solution of 100 ml of ethyl acetate and 30 ml of acetone, then filtered. A product crystallized as the solvent was removed under vacuum. The residue was mulled in ethyl ether to yield 2.2 grams of white crystalline gitoxigenin. On HPLC using system C as in Example 1. gitoxigenin had a retention time of 13.9 minutes, compared to a starting material reference gitoxin at 20.7 minutes. On TLC using system B gitoxigenin showed a blue fluorescent spot at Rf 0.69, compared to gitoxin at Rf 0.23. The product was about 95% pure gitoxigenin.

Provenance & Evidence