Study On New Removal Methods Of Protecting Group AZXMB And Synthesis Of 2-Deoxy-D-Ribose

1.Research on the new removal method of protective AZMBThe use of a protecting group must selectively react and provide a stable protected substrate in high yield for participation in the next reaction.The protecting groups must also be selectively removed by readily available,inexpensive green reagents and separated from the relevant by-products.Because there are many factors to be considered when selecting a protecting group,there is no perfect protection base so far.It is necessary to develop new protection bases and optimize the protection conditions and removal conditions of existing protection bases.In this paper,zinc,copper sulfate and acetic acid were used to reduce the azide on the protective group azidomethylbenzoyl?AZMB?to achieve the purpose of removing the protective group AZMB,and a new removal method was used.Related substrates were studied.1)The AZMB-protected substrate was used to screen the solvents,temperature,copper sulfate and CH₃COOH equivalents and concentrations required for the reaction during the experiment.The study found that water must be combined with solvents such as 1,4-dioxane,acetonitrile and tetrahydrofuran to form a co-solvent.The new removal conditions can achieve deprotection at room temperature,but if the temperature is too high at the time of deprotection,other protecting groups will also be removed and the deprotection yield will be low.No addition of copper sulfate has no effect on the reaction process,but it affects the post-treatment process,so an appropriate amount of copper sulfate needs to be added during the reaction.According to the experimental results,the deprotection yield is best when the CH3COOH is controlled at 3eq to 5eq,and the substrate concentration is controlled at about 0.2mol/L.2)In the conventional process of selectively removing the protecting group AZMB by reducing conditions,since these reducing substances also remove the protecting groups such as the benzyl group and the allyl group,the conventional removing method has certain limitations.The novel removal methods described here can remove AZMB at different sites of different sugars.At the same time with acetyl?Ac?,benzoyl?Bz?,p-methoxyphenyl?Mp?,tert-butyldiphenylsilyl?TBDPS?,benzyl?Bn?,allyl?All?,acetone fork,silicon fork and other protective groups are orthogonally removed,and the deprotected product can be quickly and efficiently obtained in 40 min-60 min.3)The experimental results show that the glycosidic bonds can also exist stably under the new removal conditions.At the same time,a new method for the deprotection of multiple AZMB substrates also yields higher yields.2.Synthesis of 2-deoxy-D riboseIn this paper,2-deoxy-D-ribose was synthesized by the method of deoxygenation of five carbon sugars.Using D-ribose as a substrate,the anomeric position is first protected,the silicon fork is used to protect the 3,4-position hydroxyl groups,and then the 2-position hydroxyl group is iodinated,and 2-deoxygenation is achieved by iodine reduction hydrogenation,and finally deprotection is performed.The product2-deoxy-D-ribose was obtained.The method has short experimental steps,simple operation,low cost and easy availability of raw materials.Finally,the product is obtained with a high yield of 41.9%in a five-step reaction.