The experimental conditions which control the exchange from deuterium or tritium gas into the C-1 proton position of glucose in aqueous solution have been studied in detail, with a view to determining the factors which maximize exchange into glucose, but minimize exchange into the solvent water. The favoured conditions for producing glucose with close to 100% isotope labelling in the C-1 position, and with negligible formation of labelled byproducts, were a reaction time of 6 to 8 hours, a temperature of 60 °C, and a pH of 7 or higher. Pd/BaSO4 was the preferred catalyst and slow pre-addition of the deuterium or tritium gas to the catalyst bed was essential to maximize the subsequent isotope exchange into the substrate.
为了确定将交换最大化到
葡萄糖中,同时将交换最小化到溶剂
水中的因素,我们详细研究了控制
氘气或氚气在
水溶液中与
葡萄糖的C-1质子位置进行交换的实验条件。在C-1位置产生接近100%同位素标记的
葡萄糖,且标记副产物形成可忽略不计的有利条件是反应时间为6至8小时,温度为60°C,pH值为7或更高。Pd/BaSO4是首选催化剂,
氘气或氚气缓慢预添加到催化剂床层对于最大化随后与底物的同位素交换至关重要。