5-Formyl-4-methylthiophene-2-boronic acid 1,3-propanediol cyclic ester5-Formyl-4-methylthiophene-2-boronic acid 1,3-propanediol ester5-甲酰基-4-甲基噻吩-2-硼酸 1,3-丙二醇酯5-(1,3,2-Dioxaborinan-2-yl)-3-methylthiophene-2-carboxaldehyde2-(2-Formyl-3-methylthien-5-yl)-1,3,2-dioxaborinane