42537-02-0Relevant articles and documents
Route Scouting towards a Methyl Jasmonate Precursor
Chapuis, Christian,Walther, Eric,Robvieux, Fabrice,Richard, Claude-Alain,Goumaz, Laurent,De Saint Laumer, Jean-Yves
, p. 95 - 109 (2016/03/19)
For the synthesis of methyl jasmonate (1), via the strategic intermediates 3, 4, and 6a, we constructed a synthetic network via the diverse intermediates 7-10, 13, 14, 17, and 18. This allowed us to compare the efficiency of more than 20 novel routes. The most productive pathway with a total yield of 38% is represented by the sequence→5a→5m→13b→13a→6a→4 and proceeds via sequential bromination, basic elimination, decarbomethoxylation, isomerization, and finally Lindlar hydrogenation. The shortest selective way, 2a→[(E,E)-12b]→3→4, is a two-pot sequence using a modification of Naef's method, based on an aldol condensation between inexpensive cyclopentanone (2a) and crotonaldehyde, with in situ Corey-Chaykovsky cyclopropanation under phase transfer conditions. The key intermediate 3 was then simply pyrolyzed to afford 4 in 27% total yield. The alternative isomerization method via the six-step deviation→5a→5c→8c→13a→6a→4 was longer, although more efficient, with a total yield of 32%. Alternatively, a yield of 34% was obtained via the five-step sequence→5a→5c→2h→2i→4. Another favored six-step pathway,→5a→5c→2h→17a→14a→4 afforded the target compound in 35% total yield.
