2,3,4,6-四-氧-乙酰基-1-溴-1-氯-β-D-吡喃糖的超声波合成

Ultrasound Synthesis of 2,3,4,6-Tetra-O-acetyl-1-chloro-1-bromo-β-D-pyranose

应用超声技术,在超声波辐射下,合成了若干吡喃糖溴化物及偕双卤代吡喃糖。结果表明,超声波频率、功率对反应收率、速率及选择性均有很大影响。在功率不变时,随着频率的增大,反应速率和收率也增大,选择性提高;在频率不变时,随着功率的增大,反应的收率增大,选择性提高。借助电子自旋共振(ESR)技术,证实此类超声波溴化反应是自由基反应。

1,2,3,4,6PentaOacetylβDpyranosyl bromide and 2,3,4,6tetraOacetyl1chloro1bromoβDpyranose were synthesized by ultrasound technique. Result showed that with the different power and different frequency of ultrasonic wave, the changes of power and frequency of ultrasonic wave have a deep impact on the reaction rate, yield and selectivity. At the same power, the reaction rate and yield increased and good selectivity attained with the increase of frequency. With the same frequency, the reaction yield increased and good selectivity resulted with the increasing of power. ESR technique proved that the reaction of these pyranosyl bromides is a radical reaction.