Synthesis of a novel nucleoside based on a spiroacetal framework
The first synthesis of a nucleoside analogue 1 is reported wherein the nucleobase 5-fluorocytosine is attached to a 1,6-dioxaspiro[5,5]undecane spiroacetal ring system. The spiroacetal system acts as a substitute for the sugar unit of natural nucleosides
Brimble, Margaret A.,Robinson, James E.,Choi, Ka Wai,Woodgate, Paul D.
p. 665 - 668
(2007/10/03)
Alkynyltrifluoroborates as versatile tools in organic synthesis: A new route to spiroketals
(Chemical Equation Presented) A simple and efficient two-step approach to spiroketals is described. Key steps include the preparation of functionalized hydroxyl α-alkynones by ring-opening reactions of lactones with lithium alkynyltrifluoroborates followed by a palladium-catalyzed hydrogenation/ spirocyclization of the prespiroketal intermediate.
Ring-opening of lactones with alkynyltrifluoroborates: A new route to functionalized α-alkynones
Alkynyltrifluoroborate salts, readily generated in situ by the addition of BF3·OEt2 to alkynyllithiums, were shown to mediate the regioselective acyl C-O ring cleavage of 5-, 6-, and 7-membered lactones. This novel, operationally sim