06734291 is referenced by 87 patents and cites 10 patents.

A synthesis of [2.2.1]bicyclo nucleosides which is shorter and provides higher overall yields proceeds via the key intermediate of the general formula III, wherein R

4

and R

5

are, for instance, sulfonates and R

7

is, for instance, a halogen or an acetate. From compounds of the general formula II, such as 3-O-aryl-4-C-hydroxymethyl-1,2-O-isopropylidene-&agr;-D-ribofuranose, intermediates of the general formula III are suitable for coupling with silylated nucleobases. Upon one-pot base-induced ring-closure and desulfonation of the formed [2.2.1]bicyclo nucleoside, a short route to each the LNA (Locked Nucleic Acid) derivatives of adenosine, cytosine, uridine, thymidine and guanidine is demonstrated. The use of the 5′-sulfonated ring-closed intermediate also allows for synthesis of 5′-amino- and thio-LNAs

Title
Synthesis of [2.2.1]bicyclo nucleosides
Application Number
10/233177
Publication Number
6734291 (B2)
Application Date
December 16, 2002
Publication Date
May 11, 2004
Inventor
Henrik M Pfundheller
Frederiksberg
US
Jef Fensholdt
Søborg
US
Alexei Kochkine
København
US
Agent
Edwards & Angell
US
Agent
Christine C O&apos Day
US
Peter F Corless
US
Assignee
Exiqon
US
IPC
C07H 15/04
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