Patent ID: 7125983

Claim:
A process for producing L-thymidine comprising: (a) a step of reacting L-arabinoaminooxazoline represented by the following formula (1) with an acrylic acid derivative represented by the following formula (2) (wherein R1 is a lower alkyl group, and X is chlorine, a p-toluenesulfonyloxy group or a methanesulfonyloxy group) to synthesize a L-arabinoaminooxazoline derivative represented by the following formula (3) (wherein X and R1 have the same definitions as given above), (b) a step of reacting a base with the L-arabinoaminooxazoline derivative represented by the formula (3) to synthesize a L-2,2 anhydronucleic acid derivative represented by the following formula (4) (c) a step of isomerizing the L-2,2 anhydronucleic acid derivative represented by the formula (4) to synthesize 2,2 anhydro-1-((-L-arabinofuranosyl)thymine represented by the following formula (5) (d) a step of subjecting the 2,2 anhydro-1-((-L-arabinofuranosyl)thymine represented by the formula (5) to halogenation and subsequent protection, or protection and subsequent halogenation, or protection and simultaneous halogenation to synthesize a 2 position-halogenated L-thymidine derivative represented by the following formula (6) (wherein R2 and R3 are each independently a protecting group for hydroxyl group, and Y is a halogen atom), (e) a step of dehalogenation of the compound represented by the formula (6) to synthesize a L-thymidine derivative represented by the following formula (7) (wherein R2 and R3 have the same definitions as given above), and (f) a step of deblocking the compound represented by the formula (7) to synthesize L-thymidine.