20073-13-6Relevant articles and documents
Synthesis of (±)-methyl epijasmonate and (±)-methyl dihydroepijasmonate by diastereoselective protonation
Krause, Norbert,Ebert, Sophia
, p. 3837 - 3841 (2007/10/03)
The synthesis of (±)-methyl epijasmonate (1) was carried out by Michael addition of lithium diallylcuprate to enone 3 and diastereoselective enolate protonation with the chelating proton source 2-(methyliminomethyl)phenol (4; 85% ds), followed by ozonolysis, oxidation, esterification, and Lindlar hydrogenation. During the ozonisation, epimerization to the thermodynamically more stable trans-isomer takes place to some extent, so that 1 was isolated with a cis:trans ratio of 72:28. The analogous transformation of enone 7 with lithium diallylcuprate and 2-(methyliminomethyl)phenol (4) furnished ketone 8 with 94% ds; this was then transformed into (±)-methyl dihydroepijasmonate (2) with a cis:trans ratio of 91:9. The olfactory properties of this product are superior to those available from commercial sources.
Behaviour of monocomplexed 1,4-diynes in the Khand reaction and use of ethylene equivalent techniques in a convenient route to tritium-labelled methyl jasmonate
Kerr, William J.,McLaughlin, Mark,Pauson, Peter L.
, p. 118 - 124 (2007/10/03)
1,2-Complexed hexacarbonyl(hepta-1,4-diyne)dicobalt, obtained from hexacarbonyl(propargyl acetate)dicobalt with tri-1-butynylaluminium, has been converted, by selective Khand annulation of the complexed triple bond with vinyl benzoate, to 2-pent-2-yn-1-ylcyclopent-2-en-1-one. By use of standard procedures this alkynyl cyclopentenone has been transformed into methyl jasmonate, allowing replacement of the final hydrogenation step by tritiation to produce the labelled analogue. Two alternative approaches to the intermediate pentynylcyclopentenone were examined and shown to be unsuccessful.
Vitamin-B12-catalyzed C,C-bond formation: Synthesis of jasmonates via sequential radical reaction
Busato,Scheffold
, p. 92 - 99 (2007/10/02)
The Cbl-catalyzed electroreduction of 3-(2'-bromo-1'-ethoxyethoxy)cyclopenten (1a) in presence of 1-cyanovinyl-acetate (8) gave, in a sequential radical reaction (5-exo-trig-cyclization of 1a following by addition to 8), 1-cyano-2-(2'-ethoxy-hexahydro-2'H-cyclopenta[b]furan-4'-yl)ethyl acetate (10a). This intermediate was transformed to methyl jasmonate (7; four steps) and epituberolide (9; three steps) in 20 and 31% yield, respectively, from cyclopent-2-en-1-ol.