Enzymes in organic synthesis. 27. Lipase-Catalyzed Synthesis of (5R,6S)-6-Acetoxyalkan-5-olides - homologues of the mosquito oviposition attractant pheromone
作者:B. Henkel、A. Kunath、Hans Schick
DOI:10.1002/prac.19973390176
日期:——
Sixteen homologous (5R*,6S*)-6-hydroxyalkan-5-olides rac-5 and their acetoxy derivatives rac-6 were synthesized from the corresponding methyl (Z)-alk-5-enoates 3 by osmium(VIII) oxide catalyzed cis-hydroxylation to the dihydroxy esters rac-4 and hydrolysis of these esters followed by lactonization. Pancreatin-catalyzed lactonization of the dihydroxy esters rac-4 afforded enantiomerically enriched hydroxy lactones ent-5, five of which were obtained enantiomerically pure by recrystallization. Acetylation of the 6-hydroxyalkan-5-olides rac-5 by vinyl acetate catalyzed by the lipase SP 526 provided enantiomerically enriched 6-acetoxyalkan-5-olides 6 with an enantiomeric excess of more than 90% in nine cases. These compounds are known as mosquito oviposition attractant pheromone (6h) or its homologues.
KELKAR, S. V.;REDDY, G. BHASKAR;KULKARNI, G. H., INDIAN J. CHEM. B, 28,(1989) N1, C. 980-981
作者:KELKAR, S. V.、REDDY, G. BHASKAR、KULKARNI, G. H.
DOI:——
日期:——
Facile Total Synthesis and Antimicrobial Activity of the Marine Fatty Acids (<i>Z</i>)-2-Methoxy-5-hexadecenoic Acid and (<i>Z</i>)-2-Methoxy-6-hexadecenoic Acid
作者:Néstor M. Carballeira、Anastacio Emiliano、Norali Hernández-Alonso、Fernando A. González
DOI:10.1021/np980274o
日期:1998.12.1
The totalsynthesis of the naturallyoccurring (Z)-2-methoxy-5-hexadecenoic acid and (Z)-2-methoxy-6-hexadecenoic acid was accomplished using as a key step Mukaiyama's trimethylsilyl cyanide addition to 4- and 5-pentadecenal, respectively. These syntheses further confirm the structures of the natural marine fatty acids and corroborate their cis double-bond stereochemistry. The title compounds were