2-溴苄醇 、
9-hydroxy-9-{3-[2,3,4,6-tetra-O-(3-methylbenzyl)-β-D-glucoyranosylthio]-2-pyrazinyl}xanthene 在
4 A molecular sieve 、 camphor-10-sulfonic acid 作用下,
反应 2.0h,
以90%的产率得到9-(2-bromobenzyloxy)-9-{3-[2,3,4,6-tetra-O-(3-methylbenzyl)-β-D-glucopyranosylthio]-2-pyrazinyl}xanthene