Chemistry Letters, Vol.36, No.1, 40-41, 2007
An expeditious synthesis of lasofoxifene and nafoxidine via the novel three-component coupling reaction
The simple and efficient synthesis of lasofoxifene (4), a possible candidate for alleviating osteoporosis, via the novel three-component coupling reaction among 4-pivaloyloxybenzaldehyde (5), cinnamyltrimethylsilane (6), and anisole in the presence of HfCl4 is illustrated. The successive cationic cyclization of the coupling product, olefin formation, and migration of the double-bond are performed to afford the common synthetic intermediate of lasofoxifene (4) and nafoxidine (3) via a very concise procedure.