• YAKHAK HOEJI
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• v.47 no.5
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• pp.271-275
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• 2003

Easy and efficient synthetic route of novel 4'-C methyl branched carbocyclic nucleosides is described. The installation of alkyl and aryl groups at 4'-position of carbocyclic nucleosides were successfully made via sequential [3,3]-sigmatropic rearrangement and ring-closing metathesis (RCM) starting from simple ketones such as acetol. Adenine and uracil were coupled via Pd(0) catalyzed reaction, followed by desilylation to give novel compounds 13 and 14, respectively.

• Bulletin of the Korean Chemical Society
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• v.29 no.4
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• pp.847-850
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• 2008

Novel mercaptophenyl carbocyclic C-nucleoside analogue was synthesized via a cyclopentenol intermediate 10, which was prepared using a sequential [3,3]-sigmatropic rearrangement and ring-closing metathesis (RCM). Friedel-Crafts alkylation was then used to couple the thiophenol.

• Bulletin of the Korean Chemical Society
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• v.24 no.9
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• pp.1289-1292
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• 2003

An efficient synthetic route for preparing novel $4'{\alpha}$-C phenyl branched carbocyclic nucleoside is described. The installation of phenyl group at the $4'$-position of carbocyclic nucleoside was successfully accomplished via a sequential [3,3]-sigmatropic rearrangement and ring-closing metathesis (RCM) beginning from simple ketone such as 2-hydroxy acetophenone.

• YAKHAK HOEJI
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• v.47 no.6
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• pp.417-421
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• 2003

This paper describes a synthetic route to novel 2'-methyl and 4'-hydroxy carbocyclic nucleosides. The methyl group was successfully installed by carbonyl addition reaction of isopropenyl magnesium bromide followed by ring-closing metathesis and the hydroxy group was directly introduced from carbohydrate chiral template "D-lactose".ose".uot;.

• Bulletin of the Korean Chemical Society
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• v.29 no.5
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• pp.993-997
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• 2008

Two directional ring-closing metathesis (RCM) was applied successfully to the synthesis of 4'-vinylated carbocyclic nucleoside analogues from the trivinyl intermediate 12, which was readily made using a sequential Claisen rearrangement and ring-closing metathesis (RCM) starting from Weinreb amide 5. An antiviral evaluation of the synthesized compounds against various viruses such as HIV, HSV-1, HSV-2 and HCMV revealed that the guanine analogue 20 have moderate anti-HIV activity in the MT-4 cell line ($EC_{50}$ = 10.2 $\mu$ M).

• Bulletin of the Korean Chemical Society
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• v.29 no.4
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• pp.755-757
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• 2008

A short and highly efficient synthetic method to prepare synthetically useful tetrahydroindolizinone derivatives from the ring-closing metathesis of N-allyl-5-allyl-5-hydroxylactams is described.

• Bulletin of the Korean Chemical Society
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• v.30 no.5
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• pp.1147-1151
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• 2009

The synthetic route of novel 3′-C-methyl carbodine analogue is described. The construction of tertiary alcohol at 3′- position of carbodine analogues was successfully made via sequential [3,3]-sigmatropic rearrangement, ring-closing metathesis (RCM) and stereoselective dihydroxylation reactions starting from ethyl glycolate.

• Bulletin of the Korean Chemical Society
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• v.29 no.9
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• pp.1723-1728
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• 2008

An efficient synthetic route for carbocyclic versions of stavudine analogues and their evaluation on antiviral activity are described. The construction of an ethynylated quaternary carbon at the 4'-position of carbocyclic nucleosides was accomplished using Claisen rearrangement of 11 and ring-closing metathesis (RCM) of dienyne 14 as key transformations. An antiviral evaluation of the synthesized compounds, 20, 21, 22, and 25 against HIV-1, HSV-1, HSV-2, and HCMV showed that only the guanine analogue 25 is moderately active against HIV-1 in the MT-4 cell line ($EC_{50}$ = 11.91 $\mu$mol).

• Bulletin of the Korean Chemical Society
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• v.22 no.11
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• pp.1179-1180
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• 2001

• Bulletin of the Korean Chemical Society
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• v.32 no.4
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• pp.1146-1152
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• 2011

The discovery of 2'-spirocyclopropyl-ribocytidine (J. Med. Chem. 2010, 53, 8150-8160) as a potent inhibitor of RNA synthesis by NS5B ($IC_{50}=7.3{\mu}M$), the RNA polymerase encoded by hepatitis C Virus (HCV), has led to the synthesis and biological evaluation of several carbocyclic versions of 2'-spiropropyl-nucleosides. The cyclopentenol intermediate 7 was successfully constructed via ring-closing metathesis (RCM) from divinyl 6. Spirocyclopropanation of enone 8 was effected by using (2-chloroethyl)-dimethylsulfonium iodide and potassium tert-butoxide to form the desired intermediate 9. The synthesized nucleoside analogues 21-24 were assayed for their ability to inhibit HCV RNA replication in a subgenomic replicon Huh7 cell line. Among them, the cytosine nucleoside analogue 22 exhibited significant anti-HCV activity ($EC_{50}= 8.2{\mu}M$).