| 摘要 |
<p>NEW MATERIAL:A furan of formula I [A is lower alkylene; R<1> is carboxy, hydroxy, lower alkoxycarbonyl, lower alkoxycarbonylamino, lower alkanoyloxy; R<2> is H, halogen, halo-lower-alkyl; R<3> is H, halogen; R<4> is H, hydroxy, carboxy, lower alkoxy, lower alkanoyloxy; R<5> is H, halogen, or R<4> and R<5> incorporate to form =CH2; F is number of double bonds, 0 or 1, n is 0 in case of F=1] or its salt. EXAMPLE:5-(3-Benzyloxypropyl)-2-oxo-4-phenyltetrahydro-3-furancarboxylic acid. USE:A remedy of diabetic cataract. PREPARATION:For example, the reaction of a compound of formula II (R<1>a is hydroxy-protecting group) with malonic acid in the presence of a base gives a compound of formula I .</p> |
