Benzaldehyde, 4-hydroxy-3-iodo-5-methoxy- → rac-3-[(3,4-Dihydro-6-hydroxy-2,5,7,8-tetramethyl-2H-1-benzopyran-2-yl)ethynyl]-4-hydroxy-5-methoxybenzaldehyde

Beteiligte Stoffe

Reaktionsschritte

Rac-3,4-dihydro-2-ethynyl-2,5,7,8-tetramethyl-2H-1-benzopyran-6-ol, 2.3 g, was reacted with 4.17 g (15 mmol) of 5-iodovanilline as described in example 1, but extending the reaction time to 4.5 hours. After the usual workup, the residue was chromatographed over 150 g of silica gel using 10% (V/V) of ethyl acetate in methylene chloride. Crystallization from ether/hexane and recrystallization from ethyl acetate/hexane yielded colorless crystals with m.p. 158°-160°.

Herkunft & Nachweise