Effect of the alkylating agent nature in the case of O- and C-alkylation of both ethyl acetoacetate and acetylacetonate anions is reported. The value of the O/C-ratio depends on three factors: the polar effect of the alkyl substituents in the alkylating agents, the steric effect of the alkyl groups and the symbiotic effect of the leaving groups. The relative contributions of the first two effects depends
‘Alk-l-ynyllead triacetates’ as alk-1-ynyl carbocation equivalents. The α-alk-1-ynylation of β-dicarbonyl compounds and nitronate salts
作者:Mark G. Moloney、John T. Pinhey、Eric G. Roche
DOI:10.1016/s0040-4039(00)85124-2
日期:1986.1
alk-l-ynyltrimethylstannane results in the rapid formation of trimethylstannyl acetate and an unstable species, believed to be the corresponding alk-l-ynyllead triacetate, which can effect the rapid α-alkynylation of β-dicarbonylcompounds and nitronatesalts.
作者:Ramakrishna Samala、Balaram Patro、Manas K. Basu、N.S. Kameswara Rao、K. Mukkanti
DOI:10.1016/j.tetlet.2013.04.110
日期:2013.7
A faciletotalsynthesis of the microbial natural products gymnoconjugatin A and B, isolated from soil microbe of Gymnoascus reessii has been accomplished using inexpensive raw materials, furfural and trans-methyl crotonate using Horner–Wadsworth–Emmons (HWE) and Wittig reactions.