Singlet oxygen addition to chiral allylic alcohols and subsequent peroxyacetalization with β-naphthaldehyde: synthesis of diastereomerically pure 3-β-naphthyl-substituted 1,2,4-trioxanes
作者:Axel G. Griesbeck、Tamer T. El-Idreesy、Johann Lex
DOI:10.1016/j.tet.2006.05.093
日期:2006.11
The synthesis of a series of eight β-naphthyl-substituted 1,2,4-trioxanes 3a–h by a sequence of singlet oxygen ene reaction of allylic alcohols 1a–h and Lewis acid catalyzed peroxyacetalization of the allylic hydroperoxides 2a–h with β-naphthaldehyde is reported. The ene reactions were performed by solid-state photooxygenation in dye-crosslinked polystyrene beads and resulted in mixtures of diastereoisomeric
cyclohexane-1,4-dione with allylichydroperoxides 2a-d, bearing an additional hydroxy group in the homoallylic position, by diastereoselective photooxygenation of allylic alcohols 1a-d and subsequent BF3-catalyzed peroxyacetalization with the diketone. From the reaction of a monoprotected cyclohexane-1,4-dione 5 with the allylichydroperoxide 6 derived from the singletoxygenation of methyl hydroxytiglate
410. Alkenylation by use of lithium alkenyls. Part I. The condensation of isobutenyl-lithium with benzaldehyde and acetophenone, and the oxotropic rearrangement of the resulting carbinols. (Studies in molecular rearrangement. Part III.)