Focusing on green chemistry protocols, a series of carbohydrate derivatives (5a–l) have been synthesized by Fischer glycosylation of α-D-glucose, D-xylose, and α-maltose with several nonpolar phenolic ester aglycones (3a–d) derived from menthol by employing solid-supported Si-H+ as the catalyst. In order to study the extent of mesomorphism in target molecules, the thermotropic behaviour has been studied by using the thermoanalytic DSC/TGA technique and polarized optical microscope. Phase transitions in the DSC thermograms of 5a–l with two endothermic melting point peaks and various exothermic crystalline transitions exhibits the existence of mesophases. However, optical photomicrographs revealed that the new glycopyranosides formed smectic A phases. Moreover, all the compounds (3a–d and 5a–l) were confirmed by FTIR and 1H NMR.

中文翻译：

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酚酯O-连接吡喃糖苷的绿色合成表征和热致行为

着眼于绿色化学方案，通过 α-D-葡萄糖、D-木糖和 α-麦芽糖的 Fischer 糖基化，合成了一系列碳水化合物衍生物 (5a-l)，其中有几种非极性酚酸酯苷元 (3a-d)使用固体负载的 Si-H+ 作为催化剂制备薄荷醇。为了研究目标分子的介晶程度，使用热分析 DSC/TGA 技术和偏光显微镜研究了热致行为。具有两个吸热熔点峰和各种放热结晶转变的 5a-l DSC 热谱图中的相变表明存在中间相。然而，光学显微照片显示新的吡喃糖苷形成近晶 A 相。此外，所有化合物（3a-d 和 5a-l）均通过 FTIR 和 1H NMR 确认。