195873-70-2Relevant articles and documents
Rhodium-Catalyzed Methylenation of Aldehydes
Lebel, Helene,Paquet, Valerie
, p. 320 - 328 (2007/10/03)
The rhodium-catalyzed methylenation of aldehydes using trimethylsilyldiazomethane and triphenylphosphine produces a variety of terminal alkenes in excellent yields. These mild and nonbasic reaction conditions allow the conversion of enolizable substrates (keto aldehydes and nonracemic α-substituted aldehydes) to terminal alkenes without epimerization. Optimization of the reaction conditions led to the conclusion that a variety of rhodium(I) sources can be used as catalysts. The effect of the solvent on the reaction has also been studied, and it indicates that although the THF is the best solvent, other solvents may be used. The reactivity of the system is very much dependent on the nature of the phosphine reagent. The use of an easily removable phosphine is also described. Spectroscopic studies indicate that the reaction proceeds via an unusual mechanism which leads to the in situ formation of the salt-free phosphorus ylide, methylenetriphenylphosphorane.
A straightforward synthesis of perbenzylated conduritols from alditols by ring closing olefin metathesis
Gallos, John K.,Koftis, Theocharis V.,Sarli, Vassiliki C.,Litinas, Konstantinos E.
, p. 3075 - 3077 (2007/10/03)
The synthesis of perbenzylated conduritols A, E and F has been achieved in six steps by formal conversion of galactitol, D-mannitol and D-glucitol into the respective terminal dienes, followed by ring closing olefin metathesis. The Royal Society of Chemistry 1999.
