Stereospecific synthesis of (+/-)-1,2-anhydro methyl rocaglate.

The rocaglates and analogues thereof have recently become targets for synthesis because of their potent antitumor activity. One of the major difficulties has been the control of stereochemistry of the adjacent -Ph and -An groups. In this letter we show that 14 is converted into 5 as a single stereoisomer and subsequently transformed into 1,2-anhydro methyl rocaglate 20.

Enantioselective alkylative double ring-opening of epoxides derived from cyclic allylic ethers: synthesis of enantioenriched unsaturated diols.

A screen of external chiral ligands has led to enantioselective organolithium-induced alkylative double ring-opening of 3,4-epoxytetrahydrofuran 1 with n-BuLi to give 3-methyleneheptane-1,2-diol 3 in 75% yield and 55% ee in the presence of bisoxazoline 10, and in up to 60% ee in the presence of (-)-sparteine 2. Extending the alkylative double ring-opening reaction to epoxides derived from oxabicyclo[n.2.