Synthesis Of Five - Membered Carbocyclic Nucleoside Precursors

Carbocyclic nucleoside antiviral drugs have attracted great attention during the last several decades. In this thesis, a series of specific functional groups and stereo-configuration five-member carbocyclic nucleoside precursors were synthesized in high yields by using plenty of achiral materials and natural compounds.Enzymatic ring cleavage of racemic2-azabicyclo[2.2.1]hept-5-en-3-one gave the corresponding amino acid and lactam in a high stereoselectivity. During the resolution, solvent, consistency of the enzyme, amount of water and reaction temperature were optimized. The target compounds were obtained after Boc protection, epoxidation, reduction and reductive ring-opening of the lactam, as well as, esterification, Boc protection, reduction, epoxidation and reductive ring-opening of the amino acid. The functional groups transformation was simply realized through three-step reactions. The protocol has many attractive advantages such as cheap raw materials, mild reaction conditions, simple work-up procedure, and high yields, which is also suitable for scale-up in the industry.