Total Stereospecific Synthesis of (3E,7Z)-Tetradecadienyl Acetate,the Major Sex Pheromone Component of the Potato Pest Symmetrischema tangolias

Chemistry of Natural Compounds - (3E,7Z)-Tetradecadienyl acetate, the major sex pheromone component of the potato pest Symmetrischema tangolias (Gyen), was stereoselectively synthesized from the...     

欧洲葡萄花翅小卷蛾性信息素

欧洲葡萄花翅小卷蛾的性信息素主要成分为7E,9Z-十二碳二烯乙酸酯。从1,5-二溴戊烷出发,制成格氏试剂后与甲醛发生格氏加成反应得到1,7-庚二醇,单酯化得到7-羟基庚醇乙酸酯,氧化得到7-氧代庚醇乙酸酯,与(2,2-二甲氧基乙基)三苯基溴化膦进行Wittig反应并水解得到9-氧代-7E-壬烯乙酸酯,再与正丙基三苯基溴化膦进行Wittig反应合成了7E,9Z-十二碳二烯乙酸酯,总产率13%,其结构经¹H NMR和¹³C NMR确证。     

A New Highly Stereospecific Synthesis of (E,Z)-2,13-Octadecadienyl Acetate,A Sex Pheromone Component of Some Lepidoptera Species

The synthesis of the Z moiety of the title compound has been achieved by carbocupration of acetylene followed by alkylation with the appropriate organozinc reagent in the presence of catalytic pd°. The coupling of this intermediate with protected propargyl alcohol after adequate fonctionalisation affords the desired enyne in good yield. The stereoselective reduction of the triple bond followed by acetylation provides the pheromone in 99.8% stereoisomeric purity.     

甘薯象鼻虫信息素(E)-2-丁烯酸-(Z)-3-十二烯基酯的全合成

性信息素;甘薯象鼻虫信息素(E)-2-丁烯酸-(Z)-3-十二烯基酯的全合成     

二化螟性信息素组分(Z）-13-十八碳烯醛的合成

利用炔化物路线合成二化螟性信息素-（Z）-13-十八碳烯醛（1）。以1,12-十二烷二醇为原料,经单边溴化,羟基保护,偶联反应,选择性还原,去保护,氧化得到目标产物。反应共6步,总产率可达45%,各产物结构经¹H NMR确认。      

A Convenient Synthesis of (Z)-7-Nonadecen-Ll-One and (Z)-7-Eicosen-Ll-Cne -the Pheromones of Peach Fruit Moth

In 1977 Tamaki¹ et al have isolated and synthesized² (Z)-7-nonadecen-ll-one (la) and (Z)-7-eicosen-l1-one (1b) which are active components of the female sex pheromones of the peach fruit moth Carposina niponensis Walsingham, a major economic pest of apple, peach and other fruits of Japan. We report in this communication a practical, convenient and stereospecific route to 1a and 1b.     

Stereoselective Synthesis of (Z)- and (E)-Allylic Silanes by Copper-Mediated Substitution Reactions of Allylic Carbamates with Grignard Reagents

Both (Z)- and (E)-allylic silanes were prepared with high stereoselectivity by the copper-mediated substitution of allylic carbamates by organometallic reagents. The reaction of alkylmagnesium reagents with (E)-allylic carbamates provides (Z)-allylic silanes, whereas both alkylmagnesium and alkyllithium reagents react with (Z)-allylic carbamates to afford (E)-allylic silanes. Because Grignard reagents are often more facile to prepare than alkyllithium species, these reagents are the optimal nucleophiles for the synthesis of both (Z)- and (E)-allylic silanes. This method also allows readily available nonracemic allylic carbamates to be converted to chiral, nonracemic (Z)- and (E)-allylic silanes with high stereoselectivity.     

Preparation of 1,3-Dienes,its Application to the Synthesis of (Z,E)-9,11-Tetradecadienyl Acetate and (E,E)-10,12-Hexa-decadienal: Sex Pheromones of Cotton Pests

E-2-Penten-4-yn-1-ol (3) has been utilized as a source for 1,3-diene systems by employing lithium amide induced alkylation, and curpous iodide catalysed Grignard coupling reaction as key steps. Its application for the synthesis of (Z,E)-9,11-tetradecadienyl acetate and (E,E)-10,12-hexadecadienal is described.     

Facile Synthesis of (Z,E)-9,11-Hexadecadienal,the Major Sex Pheromone Component of the Sugarcane Borer Diatraea saccharalis: An Efficient Strategy for Synthesis of (Z,E)-Dienic Pheromones

Practical and improved procedures for the synthesis of 7-bromo-(Z,E)-4,6-heptadienal by Pd(II)-catalyzed coupling reaction were developed. Based on the improved method, an efficient and stereoselective synthesis of (Z,E)-9,11-hexadecadienal, the main pheromone component of the sugarcane borer, Diatraea saccharalis, was achieved in 38% overall yield, which more desirable then previously reported methods. The stereochemistry relied on cross-coupling between Grignard reagent and protected 7-bromo-(Z,E)-4,6-heptadienal. The concise and facile synthetic strategy described herein provided a generally synthetic approach to other (Z,E)-dienic compounds.     

(Z)-α-Selanyl Alkenyl Grignard Reagents as Convenient Precursors for Stereoselective Synthesis of Trisubstituted Alkenes

(Z)-α-Selanyl alkenyl Grignard reagents 2 were prepared conveniently by treatment of (-bromovinylselenides 1 with magnesium filings in THF. Intermediates 2 were reacted with alkyl iodides in the presence of CuI or Pd(PPh3)4 to afford (Z)-1,2-disubstituted vinylselenides 3, which were cross-coupled with Grignard reagents in the presence of (PPh3)2NiCl2 to give trisubstituted alkenes 4 stereoselectively in good yields.     

Stereoselective Syntheses of (E)-7, (Z)-9 Dodecadien-1-Yl Acetate

Two convenient synthetic methods for (E)-7, (Z)-9 dodecadien-1-yl acetate, via palladium-copper catalysed réactions of acetylenic intermediates with vinylic halides, are presented.     

高立体选择性合成及鉴定(9E,11E)-十四碳二烯-1-乙酸酯(淡褐苹果蛾性信息素)

根据Schlosser-Wittig反应，采用溴代ω－羟基壬烷基三苯基膦盐与2E－戊烯醛反应，产物经进一步酯化生成淡褐苹果蛾性信息素－（9E，11E）－十四碳二烯－1－乙烯酯，产物中（9E，11E）异构体含量可达98％。     

Synthesis of the Sex Attractant (7Z,11Z)-Hexadecadienal of the Citrus Leafminer Moth,Phyliocnietis Citrella Stainton

A component (7Z,11Z)-hexadecadienal of the sex attractant of the citrus leafminer moth was synthesized through a new (C₆ + C₃) + C₇ approach.     

Electrochemical Synthesis of the Sex Attractant Pheromone of the Housefly: (Z)-9-Tricosene

The electrochemical synthesis of muscalure, (Z)-9-tricosene( 1 ), has been carried out by coelectrolysis of erucic acid ( 2 ) and propionic acid ( 3 ) in an undivided cell in methanol. To optimize the yield of the cross coupled product 1 , the reaction has been studied in detail by varing different parameters, viz., electrode material, current density, molar ratio of 2 to 3 , degree of partial neutralization and quantity of water in methanol.     

(Z)-a-Selanyl Alkenyl Grignard Reagents as Convenient Precursors for Stereoselective Synthesis of Trisubstituted Alkenes

Many biologically active compounds occurring in nature possess the structural skeleton of trisubstituted alkenes1-3. Difunctional group reagents, which have two different functional groups linked to the olefinic carbon atoms, for example, Se-Zr, Se-B, Se-Sn play important roles in organic synthesis, especially in developing a lot of convenient methods for stereoselective synthesis of substituted alkenes4. Recently, Tingoli et al.5 reported that (Z)-a-selanylvinyl p-toluenesulfonates can u…