- Syntheses of 5-hexadecanolide, 6-acetoxy-5-hexadecanolide and tanikolide
-
Total syntheses of 5-hexadecanolide (1), 6-acetoxy-5-hexadecanolide (2) and tanikolide (3) are described. 1-Bromoundecane (4) and 5-benzyl-1-pentanal (5) were chosen as starting materials. Wittig olefination and Grignard addition 4 and 5 afforded the 16-carbon skeleton, which underwent a series of functional group transformations to give δ-lactone derivatives 1, 2 and 3.
- Chang, Meng-Yang,Lin, Chien-Lun,Chen, Shui-Tein
-
p. 787 - 794
(2007/10/03)
-
- Enzymes in Organic Synthesis, 23. - Chemo-Enzymatic Synthesis of (5R,6S)-6-Acetoxyhexadecan-5-olide - The Major Component of The Mosquito Oviposition Attractant Pheromone
-
The methyl ester rac-4a of (5R*,6S*)-5,6-dihydroxyhexadecanoic acid was prepared by a Wittig reaction of (4-carboxybutyl)triphenylphosphonium bromide (2) with undecanal (1) followed by esterification with methanol and cis dihydroxylation with osmium(VIII) oxide / N-methylmorpholine N-oxide.After conversion of the dihydroxy ester rac-4a into (5R*,6S*)-6-hydroxyhexadecan-5-olide (rac-5) by lactonization (5R,6S)-6-acetoxyhexadecan-5-olide (6), the mosquito oviposition attractant pheromone, was obtained by an enantioselective lipase-catalyzed acetylation with vinyl acetate.In an alternative route the dihydroxy ester rac-4a was subjected to a lipase-catalyzed lactonization, which afforded as the main product (5S,6R)-6-hydroxyhexadecan-5-olide (ent-5), the enantiomer of the deacetylated pheromone. - Key Words: 5,6-Dihydroxyhexadecanoic acid derivatives / δ-Lactones / Resolution, kinetic / Lipases / Mosquito pheromone / Pheromones
- Henkel, Birgitta,Kunath, Annamarie,Schick, Hans
-
p. 921 - 924
(2007/10/02)
-
- Oxidative Grob Fragmentation of γ-Tributylstannyl Alcohols with a Combination of Iodosylbenzene, Dicyclohexylcarbodiimide, and Boron Trifluoride
-
Exposure of cyclic γ-stannyl alcohols, prepared from cyclic vinyl ketones, to a combination of iodosylbenzene, dicyclohexylcarbodiimide, and boron trifluoride-diethyl ether in dichlorometane undergoes an oxidative Grob fragmentation to give unsaturated carbonyl compounds.The dicyclohexylcarbodiimide in this reaction apparently activates iodosylbenzene and decreases Lewis acidity of boron trifluoride.The fact that the iodine(III)-mediated Grob fragmentation proceeds stereospecifically suggests the fragmentation is concerted.The fragmentation, combined with conjugate addition of (tributylstannyl)lithium and reduction or alkylation, offers an efficient procedure for the reductive and alkylative ring opening of cyclic vinyl ketones.Since cis-benzyl ether 36, after quenching of the reaction mixture with aqueous NH4Cl, afforded the chlorostannane 37, the reaction mechanism involving the formation of iodine(III) species 32 with two oxygen ligands at iodine proposed.
- Ochiai, Masahito,Ukita, Tatsuzo,Iwaki, Shigeru,Nagao, Yoshimitsu,Fujita, Eiichi
-
p. 4832 - 4840
(2007/10/02)
-
- A SHORT, STEREODIVERGENT SYNTHESIS OF THE RACEMIC ERYTHRO AND THREO DIASTEREOMERS OF 6-ACETOXY-5-HEXADECANOLIDE, A MOSQUITO OVIPOSITION ATTRACTANT PHEROMONE
-
A versatile 3-step synthesis of the title lactones has been accomplished by the stereocontrolled addition of n-decylmetallic reagents to acrolein dimer.
- Jefford, Charles W.,Kast, JuergenJaggi, Danielle,Boukouvalas, John
-
p. 4011 - 4014
(2007/10/02)
-
- erythro-6-Acetoxy-5-hexadecanolide, the Major Component of a Mosquito Oviposition Attractant Pheromone
-
The major component of the oviposition attractant pheromone from the apical droplet of eggs of the mosquito Culex pipiens fatigans is shown by g.l.c.-mass spectrometry, microchemical methods, and synthesis to be erythro-6-acetoxy-5-hexadecanolide (1); laboratory tests have demonstrated the activity of synthetic (1).
- Laurence, Brian R.,Pickett, John A.
-
-