Antiinfluenza drug

A short, scalable synthesis of carbapyranuronic acid 259, a sialyl mimetic compound related to the antiinfluenza drug Tamiflu , was developed by Kim s group [64] from (-)-shikimic acid 169 (Scheme 41). 

One synthetic advantage of olefin metathesis is that the catalyst tolerates the presence of a variety of functional groups in the reactant. In a synthesis of the antiinfluenza drug Tamiflu (Section 23.25), for example, ring-closing metathesis was used to prepare the highly functionalized cyclohexene derivative shown in the equation. What was the reactant ... 

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