Stereoselective Synthesis and Some Properties of New Chlorodiorganotin-Substituted Macrodiolides
作者:Darío C. Gerbino、Jimena Scoccia、Liliana C. Koll、Sandra D. Mandolesi、Julio C. Podestá
DOI:10.1021/om200987t
日期:2012.1.23
Radical tandem addition of dialkyltin chlorohydrides, R2SnHCl (R = n-Bu, neophyl, Ph), to TADDOL's substituted diacrylates (4-7) led to the corresponding products of cyclohydrostannation. The new optically active chlorodialkyltin-substituted 11-membered macrodiolides were obtained in very good yields and with much higher stereoselectivity than that achieved with the corresponding monohydrides, R3SnH. Thus, the cyclohydrostannation of diacrylate 4 and dimethacrylate 5 lead to just one diastereomer in the first case and to an easily separable mixture of two diastereomers in the second. Reduction of the new organotin macrocycles with LiAlH4 afforded optically active organotin derivatives structurally related to glutaric acid. Oxidation of the new chlorodiorganotin-substituted macrocycles with 30% hydrogen peroxide gave the new 11-membered macrocycles 30 and 31 free of tin in an average total yield of 43.4% from TADDOL. Full H-1, C-13, and Sn-119 data are also reported.
Synthesis of dineophyltin dihydride and stereoselective hydrostannation of alkynes and (E)-trisubstituted alkenes
作者:Adriana E. Zúñiga、Pablo M. Fidelibus、Sandra D. Mandolesi、Julio C. Podestá
DOI:10.1016/j.jorganchem.2010.12.033
日期:2011.4
The four steps synthesis starting from benzyl chloride and Sn was shown to be more convenient than the two step direct alkylation of SnCl4. The study of the free radical hydrostannation of mono- and disubstituted acetylenes with hydride 3 shows that they are stereoselective and that the stereoisomers obtained in higher proportion are stable and easily separated by column chromatography. Some preliminary