105398-69-4Relevant articles and documents
Unified synthesis of quinone sesquiterpenes based on a radical decarboxylation and quinone addition reaction
Ling, Taotao,Poupon, Erwan,Rueden, Erik J.,Kim, Sun H.,Theodorakis, Emmanuel A.
, p. 12261 - 12267 (2007/10/03)
A unified synthesis of several quinone sesquiterpenes is described herein. Essential to this strategy is a novel radical addition reaction that permits the attachment of a fully substituted bicyclic core 16 to a variably substituted quinone 10. The addition product 15 can be further functionalized, giving access to natural products with a high degree of oxygenation at the quinone unit. The quinone addition reaction is characterized by excellent chemoselectivity, taking place only at conjugated and unsubstituted double bonds, and regioselectivity, being strongly influenced by the resonance effect of heteroatoms located on the quinone ring. These features were successfully applied to the synthesis of avarol (1), avarone (2), methoxyavarones (4, 5), ilimaquinone (6), and smenospongidine (7), thereby demonstating the synthetic value of this new method.
The invention of radical reactions. Part 39. The reaction of white phosphorus with carbon-centered radicals. An improved procedure for the synthesis of phosphonic acids and further mechanistic insights
Barton, Derek H. R.,Vonder Embse, Richard A.
, p. 12475 - 12496 (2007/10/03)
White phosphorus in tetrahydrofuran under argon reacts in a long radical chain reaction with carbon radicals derived from Barton PTOC esters. The reaction is initiated by traces of oxygen and strongly inhibited by TEMPO. From the duration of the induction period the chain length can be measured as approximately one million. Each P4 molecule can add up to two carbon radicals. Oxidation of the adducts provides a convenient synthesis of phosphonic acids in high yield. With H2O2 at 0°C oxidation to the appropriate phosphinic acids is fast. For sensitive natural products the further transformation to phosphonic acids is best carried out at room temperature with an excess of SO2. In this way even linoleic acid can be convened to the corresponding phosphonic acid in good yield without any attack on the skipped diene unit. TEMPO is also remarkable for its stabilization of white phosphorus in solution when exposed to oxygen. Likewise an ordinary phosphine, like tributyl phosphine, is also stabilized by small amounts of TEMPO.
The invention of radical reactions. Part XXXVII. A convenient radical synthesis of dialkyl diselenides from carboxylic acids
Barton, Derek H. R.,Fontana, Giovanni
, p. 11163 - 11176 (2007/10/03)
A new and convenient synthesis of dialkyl diselenides from carboxylic acids by Barton PTOC ester based radical chemistry is described. This method was especially successful when O-cholestan-3β-yl-2,2,2-trichloroselenoacetate and O-neopentyl selenobenzoate