64133-66-0Relevant academic research and scientific papers
General and highly α-regioselective zinc-mediated prenylation of aldehydes and ketones
Zhao, Li-Ming,Jin, Hai-Shan,Wan, Li-Jing,Zhang, Li-Ming
experimental part, p. 1831 - 1837 (2011/06/11)
A simple, efficient, and general R-prenylation approach for the synthesis of a variety of R-prenylated alcohols has been successfully developed. A wide range of R-prenylated alcohol derivatives could be obtained in good yields by highly R-regioselective zinc-mediated prenylation of various aldehydes and ketones with prenyl bromide at 120 °C in HMPA. By simply altering the reaciton solvent and temperature, the method allows the achievement of a highly notable opposite regiocontrol, providing the expected regiochemical product. The method provides a convenient route for the direct α-prenylation of carbonyl compounds in a highly R-regioselective manner using a cheap and convenient mediator. Two possible pathways are proposed to account for the formation of these synthetically difficult-toobtain molecules.
Total synthesis of gypsetin, deoxybrevianamide E, brevianamide E, and tryprostatin B: Novel constructions of 2,3-disubstituted indoles
Schkeryantz, Jeffrey M.,Woo, Jonathan C. G.,Siliphaivanh, Phieng,Depew, Kristopher M.,Danishefsky, Samuel J.
, p. 11964 - 11975 (2007/10/03)
A concise and efficient total synthesis of the acyl-CoA:cholesterol acyltransferase inhibitor gypsetin (1) is described. The route features a straightforward method for the introduction of a reverse prenyl group into the C2-position of an N-phthaloyl-protected tryptophan (11). The total synthesis of gypsetin was completed by the dimethyldioxirane-promoted double- oxidative cyclization of a prefashioned diketopiperazine (19). Total syntheses of deoxybrevianamide E (24) and brevianamide E (25) following similar procedures are also described. The reaction of nucleophiles with in situ-generated 3-chloroindolenines provides a route to 2,3-disubstituted indoles from 3-substituted precursors. Indications of the scope and limitations of such reactions are provided. A total synthesis of tryprostatin B (41), a diketopiperazine derived from an L-tryptophan derivative (bearing a prenyl group at the α position of the indole) and L-proline, was accomplished. The key step involved the introduction of the prenyl function onto a protected tryptophan congener (11). A route for the prenylation of ketones with virtually no competitive reverse prenylation is also provided.
Homoallylic Alcohols from Samarium Diiodide-mediated Coupling of Allylic Sulfones with Carbonyl Compounds
Clayden, Jonathan,Julia, Marc
, p. 2261 - 2262 (2007/10/02)
Reduction of allylic sulfones with samarium diiodide gives allylsamarium species which react in situ with carbonyl compounds, yielding homoallylic alcohols.
Samarium(II)-mediated reaction of allylic phosphate esters with carbonyl compounds: A new method for "Umpolung" of allylic phosphates
Araki, Shuki,Hatano, Masahiro,Ito, Hirokazu,Butsugan, Yasuo
, p. 329 - 336 (2007/10/02)
Allylic phosphates allylate ketones and aldehydes in the presence of samarium(II) iodide.The coupling proceeds with the preservation of the olefin geometry ever, regio- and stereoselectivity are not high.
