Ethers, triisopropylsilyl epoxidations

Epoxidations of triisopropylsilyl (TIS) ethers (170) and (171) with W05-HMPA in dichloroethane take place stereoselectively to furnish n-epoxides these epoxidations, along with the vanadium-catalyzed epoxidations of (152) and (153) (described in Section 3.1.3.3), make available a group of all the four possible diastereoisomeric epoxidies having four consecutive chiral centers in an acyclic carbon framework,... 

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