Gas-phase sugar formation using hydroxymethylene as the reactive formaldehyde isomer
Gas-phase sugar formation using hydroxymethylene as the reactive formaldehyde isomer
复制标题
DOI：
10.1038/s41557-018-0128-2
复制
发表时间：
2018-11-01
期刊：
影响因子：
21.8
通讯作者：
Schreiner, Peter R.
中科院分区：
文献类型：
--
作者：
Eckhardt, Andre K.;Linden, Michael M.;Schreiner, Peter R.
碳水化合物(CH2O)(N)是碳(原子)与水的形式加合物，其重复单元结构类似于H-C-OH(羟亚甲基)。虽然羟亚甲基被认为是糖形成的基石，但它是一种活性物种，直到最近才被发现。在这里，我们证明了甲醛与其异构体羟亚甲基在几乎无障碍的反应中生成乙醇醛。这种羰基烯类型的转变在没有碱和溶剂的情况下在低温下进行，类似于在外星环境或星际云中发现的那样。正如我们通过三糖甘油醛的形成所证明的那样，羟亚甲基作为迭代糖合成的基础。热力学上首选的酮糖二羟基丙酮不会形成，在这里提出的迭代合成中不太可能形成更多的支链糖。因此，这些结果提供了众所周知的福尔马糖(Butlerow)反应和非水条件下糖的形成之间的联系。
Carbohydrates (CH2O)(n) are the formal adducts of carbon (atoms) to water with a repeating unit that structurally resembles H-C-OH (hydroxymethylene). Although hydroxymethylene has been suggested as a building block for sugar formation, it is a reactive species that had escaped detection until recently. Here we demonstrate that formaldehyde reacts with its isomer hydroxymethylene to give glycolaldehyde in a nearly barrierless reaction. This carbonyl-ene-type transformation operates in the absence of base and solvent at cryogenic temperatures similar to those found in extraterrestrial environments or interstellar clouds. Hydroxymethylene acts as a building block for an iterative sugar synthesis, as we demonstrate through the formation of the triose glyceraldehyde. The thermodynamically preferred ketose dihydroxyacetone does not form, and the formation of further branched sugars in the iterative synthesis presented here is unlikely. The results therefore provide a link between the well-known formose (Butlerow) reaction and sugar formation under non-aqueous conditions.