Synthesis 3-deoxy-1, 2-O-isopropylidene-α-D-xylofuranose

AtorvastatinCa(Lipitor)is a blood-lipid lowering drug produced by Pfizer.As the most widely prescribed branded cholesterol-lowering drug and most widely prescribed medicine in the world,it greatly lowers LDL cholesterol and TG levels.In this thesis the way to synthesis of 3-Deoxy-1,2-O-isopropylidene-α-D-xylofuranose were studied.It is an asymmetric intermediation of the Atorvastatin's side chain,also is a key intermediation of medication and natural product.Several methodologies have been reviewed to synthesize 3-Deoxy-1,2-O-isopropy -lidene-α-D-xylofuranose,it was finally synthesized from D-xylose.Arising from the protection of hydroxyl group in D-xylose by acetone,Selective removal of the 3,5-O-iso -propylidene group of D-xylose(1,2-O-isopropylidene-α-D-xylofuranose 2).Benzoylated the 5-hydroxyl group of 2(5-O-benzoyl-1,2-O-isopropy-lidene-a-D-xylofuranose 3).Then replance 3-hydroxyl group of 3 by the iodide group(3-iodo-5-O-benzoyl-1,2-O-isopropy -lidene-α-D-xylofuranose 9).Next step removal of the iodide group of 9(3-deoxy-5-Obenzoyl-1,2-O-isopropylidene-α-D-xylofuranose 10). Last one to do was deprotection of hydroxyl group in the 5 position of 10(3-Deoxy-1,2-O-isopropylidene-α-D-xylofuranose 11).The total yield was 34%.In the studied some useful compound were synthesized,and their technical conditions were discussed.It is a new 6 steps route to synthetic 3-Deoxy-1,2-O-isopropylidene-α-D-xylofuranose This method is easy to apply,sufficiently mild and less harmful to the environment.The reductive reagents(e.g.,tributyltin hydride[n-Bu₃SnH].)have often been used in many radical reactions.However,organotin compounds are toxic and expensive,and are difficult to be completely removed from the desired reaction products.So,in this thesis avoided to use them.