什么是果糖? 左旋糖或果糖一已酮糖，ch2oh. (choh)3.-co.ch2oh, (f.diphosphate, f.1.6-diphosphate, the harden young ester. f.6-phosphate, the neuberg ester).它是一种非常甜物质，是水果和蜂蜜天然的副产品。果糖是另外一种单糖。酵母迅速发酵。果糖味道比葡萄糖或甚至比果糖+葡萄糖=（蔗糖）联合甜得多，即使它只含有一半卡如里，不象葡萄糖，它能用于糖尿病。它也比葡萄糖有更大的水溶性。果糖成颗粒和糖浆型。在某些液体情况是例外，如调味品或饮料，它不能替代常规糖（蔗糖），除非一配方用特殊代用品。当果糖加热会损失一些它的甜力。 查看更多
对醛基苯甲酸进行酰氯化反应时醛基需要保护吗.请帮忙看下吧？ 不必保护(1) commercially available 4-formylbenzoic acid (5.0 g, 33.3 mmol) was dissolved in a mixture of anhydrous tetrahydrofuran (100 ml) and anhydrous n,n-dimethylformamide (1 ml) and the mixture was cooled with stirring to 0.degree. c. to the resulting mixture was added dropwise oxalyl chloride (3.8 ml, 43.3 mmol). the mixture was stirred at room temperature for 30 minutes and then at 40.degree. c. for 20 minutes. the reaction mixture was concentrated under reduced pressure and then in vacuo to afford 4-formylbenzoyl chloride. 查看更多
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