Library of mild and economic protocols for the selective derivatization of sucrose under microwave irradiation
作者:M. Teresa Barros、Krasimira T. Petrova、Paula Correia-da-Silva、Taterao M. Potewar
DOI:10.1039/c1gc15228a
日期:——
The chemistry of sucrose is very challenging due to its eight hydroxyl groups, three of which are primary, with very similar reactivities, thus control of the chemoselectivity is a central issue. In this work, the selective formation of monounsaturated esters at the 6-position, by applying the Mitsunobu conditions for the selective esterification of sucrose, is reported. Also, the outcome of a number of mono-substitution reactions at positions 6 or 6′, and di-substitution reactions at positions 6 and 6′ have been explored. Mild and energy-efficient procedures, with short reaction times (5 to 10 min) using microwave irradiation have been developed, and the results compared with conventional procedures. In some cases, the use of microwave irradiation appeared to provide not only time saving but also improved selectivity.
蔗糖的化学性质非常具有挑战性,因为它有八个羟基,其中三个是伯羟基,具有非常相似的反应活性,因此化学选择性的控制是一个中心问题。在这项工作中,报道了通过应用蔗糖选择性酯化的 Mitsunobu 条件,在 6 位选择性形成单不饱和酯。此外,还探讨了位置 6 或 6' 处的许多单取代反应以及位置 6 和 6' 处的双取代反应的结果。已经开发出使用微波辐射的温和且节能的程序,反应时间短(5至10分钟),并将结果与传统程序进行了比较。在某些情况下,使用微波辐射似乎不仅可以节省时间,还可以提高选择性。