Study of the N7 Regioselective Glycosylation of 6-Chloropurine and 2,6-Dichloropurine with Tin and Titanium Tetrachloride was written by Tranova, Lenka;Styskala, Jakub. And the article was included in Journal of Organic Chemistry in 2021.Reference of 4163-60-4 This article mentions the following:
6-Chloropurine and 2,6-dichloropurine were regioselectively glycosylated at position 7 to give the corresponding peracetylated N7-nucleosides, which can be suitable for other purine transformations. In this work, we study the distribution of N7/N9-isomers produced via the Vorbruggen method under different conditions, using an N-trimethylsilylated purine derivative and SnCl4 or TiCl4 as a catalyst. The main effort is devoted to reversing the disadvantageous predominant selectivity of most glycosylation reactions at the N9 position and thus to determining conditions that maximize the regioselectivity of glycosylation toward the desired N7-isomer. In the experiment, the researchers used many compounds, for example, (2S,3R,4S,5S,6R)-6-(Acetoxymethyl)tetrahydro-2H-pyran-2,3,4,5-tetrayl tetraacetate (cas: 4163-60-4Reference of 4163-60-4).
(2S,3R,4S,5S,6R)-6-(Acetoxymethyl)tetrahydro-2H-pyran-2,3,4,5-tetrayl tetraacetate (cas: 4163-60-4) belongs to esters. Carboxylic acid esters of low molecular weight are colourless, volatile liquids with pleasant odours, slightly soluble in water. Esters are more polar than ethers but less polar than alcohols. They participate in hydrogen bonds as hydrogen-bond acceptors, but cannot act as hydrogen-bond donors, unlike their parent alcohols. This ability to participate in hydrogen bonding confers some water-solubility.Reference of 4163-60-4
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics