Sphingosine and clavaminol H derivatives bearing fluorinated chains and their cytotoxic activity

Olefin Metathesis Reactions with Fluorinated Substrates, Catalysts, and Solvents

“…The study on these model substrates was then applied to perfluorinated natural product analogues: brassinosteroids, β-cyclodextrins, and sphingosines (Scheme ) . The coupling partner required for the synthesis of brassinosteroid analogues 294 was obtained in 10 conventional steps from commercially available acid 293 .…”

Cross-metathesis reaction of α- and β-vinyl C-glycosides with alkenes

“…Running the reaction under the standard conditions in dichloromethane or toluene under reflux, the desired cross-metathesis product α- 4a was isolated in low 10% and 3% yields ( Table 1 , entries 1 and 2). Although it has been observed that the use of octafluorotoluene [ 23 , 25 – 27 ] as the solvent had a positive effect on yields, its use provided α- 4a in a low 12% yield ( Table 1 , entry 3), but its use under microwave irradiation [ 26 , 28 – 30 ] gave rise to α- 4a in 33% isolated yield ( Table 1 , entry 4). A similar result (36% yield) was obtained with a 1:1 octafluorotoluene/ClCH 2 CH 2 Cl mixture ( Table 1 , entry 5).…”

“…Our first choice was 1-heptene ( 3b ), which reacted under the above mentioned conditions (i.e., with HG II in ClCH 2 CH 2 Cl under reflux) to give the corresponding product α- 4b in 59% isolated yield ( Table 2 , entry 2). We also carried out the reaction with perfluorohexylpropene ( 3c ), because of our long term interest in the synthesis of perfluoroalkylated compounds [ 21 , 30 – 34 ] and their application [ 35 ]. The reaction furnished the desired compound α- 4c in a good 50% isolated yield ( Table 2 , entry 3).…”

Recent Advances in the Total Synthesis of Clavaminols

“…In 2012, Kotora and co-workers realized a short and straightforward protocol for the synthesis of (+)-clavaminol H containing fluorinated chains by utilizing a microwaveinduced cross-metathesis as the key reaction (Scheme 7). 19 Treatment of perfluoroalkylated propene 35 with the previously prepared enantioenriched allylic alcohol 36 in the presence of Hoveyda-Grubbs second-generation catalyst under microwave conditions 20,21…”