Scandium trifluoromethanesulfonate is found to be a Lewis acid catalyst for selective cleavage of esters containing a coordinative group adjacent to an ester moiety. The reaction proceeds under weak acidic conditions at room temperature; the catalyst can be recovered and reused. Even α-acyloxy ketones are deacetylated without racemization. Selective monodeacetylation at C-10 of paclitaxel has been achieved.
研究发现,
三氟甲磺酸钪是一种
路易斯酸催化剂,可选择性地裂解含有邻近酯分子的配位基团的酯。反应在室温下的弱酸性条件下进行;催化剂可以回收和重复使用。即使是 α-乙酰氧基酮也能脱乙酰化而不发生外消旋化。在
紫杉醇的 C-10 处实现了选择性单去乙酰化。