Syntheses of methyl dihydrojasmonate and dihydrojasmone from A butadiene telomer

Cross-condensation reactions of cycloalkanones with aldehydes and primary alcohols under the influence of zirconocene complexes

“…2-Methyl-6-octylidenecyclohexanone (4j): [M+] m/e 222; IR (NaCl) 2950, 2850, 1680, 1600, 1450, 1140 cm'1; NMR (CDCl3/Me4Si) 6.3 (t, 1 ), 2.9-1.2 (m, 19 ), 1.0 (d, 3 ), 0.8 (t, 3 H); 13C NMR (CDCl3/Me4Si) 204.1 (s), 140.0 (d), 135.2 (s), 40.0 (t), 32.0 (d), 29.0 (t), 28.5 (t), 27.9 (t), 26.5 (t), 25.0 (t), 24.0 (t), 23.3 (t), 22.6 (t), 14.0 (q), 12.3 (q). 4-Methyl-2-octylidenecyclohexanone (4k 25.4 (t), 24.0 (t), 23.3 (t), 22.6 (t), 13.8 (q), 10.4 (q).…”

“…1982, 104, 5844. jasmonate. 19 For example, methyl dihydrojasmonate has been synthesized from 2-pentyl-2-cyclopenten-l-one (8g), which is prepared via lengthy steps from l-acetoxy-2,7octadiene derived from Pd-catalyzed telomerization of butadiene in acetic acid. 20 Compound 13 has been prepared from 4h by a similar sequence of reactions as above.19…”

Applications of palladium-catalyzed or promoted reactions to natural product syntheses

“…After the introduction of the allyl group at the terminal position, the terminal double bond is unmasked to produce 2,5-undecanedione (9) example is the formation of geranylgeraniol (36) from methyl farnesoate (35) 16) (Scheme 12). Vitamin A (40) and related compounds are synthesized by the reac- J. Ts~i tion of sulfones 38 with the 7r-allyt complex 37 derived from 3-methyl-2-butenyl acetate. Reaction of the complex 37 with 3-methyl-1-phenylsulfonyl-5-(2,6,6-trimethyl-1-cyclohexen-l-yl) penta-2,4-diene (38) PaUadium-Catalyzed or Promoted Reactions to Natural Product Syntheses…”

A Highly Z-Selective Isomerization (Double-Bond Migration) Procedure for Allyl Acetals and Allyl Ethers Mediated by Nickel Complexes

“…Thus, vinyl acetals are used for the diastereoselective construction of aldol ethers and b-(N-acylamino)aldehydes (Mannich products) by Lewis acid-induced rearrangement, 5,6 and allyl vinyl ethers prepared by transition metal catalyzed rearrangement of diallyl ethers are of interest in the stereoselective synthesis of aliphatic Claisen products. [7][8][9][10] Several catalysts have been reported in the literature for the isomerization of allyl ethers and acetals, e.g., potassium tert-butoxide in DMSO 11 and Rh, Ru, Ir, and Fe complexes, or palladium on active charcoal. 12 Among them, only the potassium tert-butoxide/DMSO method leads to high Z-selectivities.…”