Journal of Organic Chemistry p. 7653 - 7660 (1994)
Update date:2022-08-03
Topics:
Sugimura, Hideyuki
Osumi, Kenji
Kodaka, Yasuko
Sujino, Keiko
The NBS-promoted coupling reaction of phenyl 3,5-O-isopropylidene-2-deoxy-1-thio-α-D-threo-pentofuranoside (5e) with silylated pyrimidine bases was found to proceed in a highly stereoselective manner (α:β = 1:24 - 0:1) to afford 2'-deoxy-β-D-threo-pentofuranosyl pyrimidine nucleosides in satisfactory yields.The highly stereoselective outcome is thought to result from an in situ anomerization-type mechanism, in which intimate ionic intermediates would be in equilibrium and anomerize to the sterically preferable α form.A subsequent SN2 type attack to the intermediate will lead to the β-nucleosides.By using this method, the synthesis of L-nucleosides, 1-(2-deoxy-β-L-threo-pentofuranosyl)thymine and cytosine derivatives, was also demonstrated by starting from the L-enantiomer of the thioglycoside.On the other hand, the reaction with purine bases was accompanied by the production of undesirable N-7 regioisomers besides the desired N-9 products.The product distribution of the regioisomers was, however, proved to change with reaction time.For instance, a long reaction period allowed the thermodynamically stable N-9 isomers to be exclusively produced with moderate selectivity (α:β = 1:2 - 1:4.8).The isolated yields to the 9-β isomers after purification were acceptable for practical use.
View MoreLiaoning Yufeng Chemical Co.,Ltd.
Contact:86-0419-3418888
Address:The metallurgical industrial zone,shoushan town, Liaoyang, Liaoning, China
Contact:+44 (0)2036089360-31
Address:Chanceryhouse,Chancery Lan
Wuhan Better Organic Technology Inc.
Contact:13307163183
Address:Wuhan Economic&Technology Development Zone, Hubei
Yicheng Goto Pharmaceuticals Co.,Ltd.
Contact:+86 710 3423122
Address:5th Floor,East Gate of Building #2,Servo-Industrial Park,1st Qilin Road,Xiangyang,Hubei,China
Winchem Industrial Co. Ltd.(expird)
Contact:86-574-83851061 86-574-87083208
Address:Room 905, No.3 Building,East Business Center, 456 Xingning Road, Ningbo City,China
Doi:10.1002/hlca.201400061
(2014)Doi:10.1021/om9706267
(1998)Doi:10.1016/j.bmcl.2015.07.056
(2015)Doi:10.1016/j.tet.2007.05.059
(2007)Doi:10.1021/acs.orglett.9b03103
(2019)Doi:10.1016/j.bmcl.2018.07.006
(2018)