- Stereoselective Synthesis of (2E,4E)- and (2Z,4E)-2,4-Alkadienoates by the Ester Enolate Claisen Rearrangement of (E)-1-Alkyl-3-trimethylsilyl-2-propenyl Glycolates Followed by the Peterson Reaction
-
The ester enolate Claisen rearrangement of (E)-1-alkyl-3-trimethylsilyl-2-propenyl glycolates gave (E)-erythro-2-hydroxy-3-trimethylsilyl-4-alkenoates with high diastereoselectivity, which were stereoselectively converted into (2E,4E)- and (2Z,4E)-2,4-alkadienoates by the Peterson reaction.
- Sato, Toshio,Tsunekawa, Hiroshi,Kohama, Hiromasa,Fujisawa, Tamotsu
-
-
Read Online
- SYNTHESIS AND CHARACTERIZATION OF ALL FOUR ISOMERS OF METHYL 2,4-DECADIENOATE FOR AN INVESTIGATION OF THE PHEROMONE COMPONENTS OF Pityogenes chalcographus
-
Methyl (2E,4Z)-2,4-decadienoate (1), an important pheromone component of Pityogenes calcographus, and its three geometrical isomers (2-4) have been synthesized and obtained in >99percent isomeric purity.Urea inclusion complexes were used in the final purification procedures.Spectroscopic data (MS, (1)H and (13)C NMR) of all four isomers are discussed.A photoisomerization study of the decadienoates is presented.
- Baeckstroem, Peter,Jacobsson, Ulla,Norin, Torbjoern,Unelius, C. Rikard
-
-
Read Online
- Microwave-accelerated Ru-catalyzed hydrovinylation of alkynes and enynes: A straightforward approach toward 1,3-dienes and 1,3,5-trienes
-
Quick, but not dirty! Microwave heating was found to have a significant effect on the Ru-catalyzed hydrovinylations of alkynes. A broad range of different terminal alkynes were coupled to methyl acrylate within just 30min in good to excellent yields (see scheme). This new protocol was transferred to the hydrovinylation of enynes as novel coupling partners in C-H-activation chemistry giving different 1,3,5-trienes as the sole products. Copyright
- Schabel, Tobias,Plietker, Bernd
-
p. 6938 - 6941
(2013/06/27)
-
- Pheromone synthesis. Part 249: Syntheses of methyl (R,E)-2,4,5- tetradecatrienoate and methyl (2E,4Z)-2,4-decadienoate, the pheromone components of the male dried bean beetle, Acanthoscelides obtectus (Say)
-
The enantiomers of methyl (E)-2,4,5-tetradecatrienoate (1), a component of the male pheromone of Acanthoscelides obtectus, were synthesized from the enantiomers of 1-undecyn-3-ol (6), which were obtained via asymmetric acetylation of (±)-1-trimethylsilyl-1-undecyn-3-ol (4) with vinyl acetate as catalyzed by lipase PS (Amano). The ortho ester Claisen rearrangement of 6 with triethyl orthoacetate was the key-step to generate the chiral allenic system. A new synthesis of (±)-1 was also executed starting from (±)-6. Three different syntheses of methyl (2E,4Z)-2,4-decadienoate (2), another component of the male pheromone of A. obtectus, were achieved by means of either palladium-catalyzed Heck reaction or a Claisen and an Al 2O3 catalyzed thermal rearrangements.
- Mori, Kenji
-
experimental part
p. 1936 - 1946
(2012/04/10)
-