Synthesis of 13-Hydroxy-9Z,11E,15Z-octadecatrienoic Acid

Stereoselective synthesis of 15,16-didehydro coriolic acid, starting from pent-2-en-4-yn-1-ol is described.     

Total Synthesis of (+)-(8S,13R)-Cyclocelabenzine

An asymmetric synthesis of the spermidine alkaloid (+)-cyclocelabenzine ( 1a ) and its (?)-(13S)-epimer 1b is described using optically active (+)-(3S)-3-amino-3-phenylpropionic acid as the chiral building block. The isoquinolin-1-one fragment 15 was synthesized by a modified Bischler-Napieralski reaction. The relative configuration of the (?)-isomer was determined by an X-ray crystal-structure analysis, which enabled us to determine the absolute configuration of natural (+)- 1a as (8S,13R).     

Total synthesis of (3Z,9Z,6S,7R) and (3Z,9Z,6R,7S)-6,7-epoxy-3,9-octadecadienes

(3Z,9Z,6S,7R)-6,7-epoxy-3,9-octadecadiene (1) and (3Z,9Z,6R,7S)-6,7-epoxy-3,9-octadecadiene (2) have been stereoselectively synthesized in eight steps from 2-pentyn-1-ol with an overall yield of 8%. The key steps involved the Sharpless asymmetric dihydroxylation of (2E)-oct-2-en-5-yn-1-ol (6). The new synthetic method is suitable for multigram-scale preparation of 1 and 2 and might be used for producing sufficient quantities of the sex pheromone components for management of the pest of tea plantations.     

Synthesis of 12(R),13(S)-oxido-9z-octadecenoic (vernolic) and 13(S)-hydroxy-9z, 11E-octadecadienoic (coriolic) acids

(-)-Vernolic acid was prepared enantiospecifically from a readily available carbohydrate precursor and Isomerized to (+)-coriolic acid using the methylmagnesium salt of     

Oxidation products of arachidonic acid I. The synthesis of methyl 8R, 11R, 15-trihydroxy-9S, 12-oxyeicosa-5Z, 13E-dienoate (19)

Diacetone glucose was converted in high yield to 3-deoxy-5-6-anhydro-1,2-0-isopropylidene-D-glucofuranose($\text{3}$), which was transformed to title compound.³ Its mass spectrum confirms the structure of a naturally occurring oxidation product of arachidonic acid first described by wolfe and Pace-Asciak.⁴     

Asymmetric total synthesis of 14(R),15(S)-, 14(S),15(R)-, 14(R),15(R)-, and 14(S),15(S)-epoxyeicosatrienoic acids

The four chiral stereoisomers of 14,15-oxido-5Z, 8Z, 11Z-eicosatrienoic acid were synthesized. The absolute stereochemistry in each case was derived from an asymmetric epoxidation of E-2-octen-1-ol.     

Asymmetric Synthesis of (-)-(2R,3R,6S)-Irnigaine

Introduction　　Asarelativelynewmemberofnaturalalkaloidswith2 ,6 disubstituted 3 piperidinolskeleton ,irnigaine 1wasisolatedfromthetubersofArisarumVulgare (Araceae)in1995byMelhaouiandBode .1Itsstructureandrelativeconfigurationswereelucidatedby1HNMRstudiesandtheabsoluteconfigurationwasproposedonthebasisofitsopti calrotation .1Soonafterthen ,Meyerandhisco workersreportedthefirstsynthesisof (- ) (2R ,3R ,6S) irni gaineandtheconfigurationconfirmation .Althoughtheirsynthesisroutewasshortan…     

(-)-(1R,2S)-肉豆蔻木脂素的不对称合成

报道了天然产物(-)-肉豆蔻木脂素的全合成. 以香草醛为起始原料, 经Wittig反应、LiAlH₄还原和Sharplass不对称双羟化等反应构建了苏式结构的中间体; 以焦性没食子酸为原料, 经Claisen重排反应制得另一种苯丙素片段; 2个中间体通过Mitsunobu反应, 缩合并使构型翻转, 得到赤式-(-)-肉豆蔻木脂素. 为赤式8-O-4′新木脂素的合成提供了一种新方法.     

(9Z,12Z,15Z)-十八碳三烯醛的GC-MS分析

（9Z，12Z，15Z）－十八碳三烯醛是美国白蛾信息素的主要成效成分之一，在其合成的过程中，采用气相色谱监测分离提纯效果；提纯的样品成分在化学方法、IR、^1H NMR波谱分析基础上用气相色谱－质谱鉴定为该化合物，并用气相色谱的面积归一化法测得其含量大于99％；该法简单、准确可靠、无需标样。     

First Total Synthesis of 12-Hydroxy-13-methylpodocarpa-9, 11, 13-trien-3-one

12-Hydroxy-13-methylpodocarpa-9, 11, 13-trien-3-one 9 was isolated from the twigs ofCroton salutaris1. Many diterpenes exhibit significant bioactivities, such as antibac-terial and antitumour and 9 has a rare structure. In order to study the relationshipb…     

On the structure of passifloricin A: asymmetric synthesis of the delta-lactones of (2Z,5S,7R,9S,11S)- and (2Z,5R,7R,9S,11S)tetrahydroxyhexacos-2-enoic acid

Stereoselective syntheses of the delta-lactone of (2Z,5S,7R,9S,11S)-tetrahydroxyhexacos-2-enoic acid, the structure reported for passifloricin A, and of its (5R)-epimer are described. The creation of all stereogenic centers relied upon Brown's asymmetric allylation methodology. The lactone ring was created via ring-closing metathesis. The NMR data of both synthetic products, however, were different from those of the natural product. The published structure of passifloricin A is thus erroneous and will require further synthetic work to be unambiguously assigned. [structure: see text]     

Synthesis of (−)‐Pinellic Acid and Its (9R,12S,13S)‐Diastereoisomer

The total synthesis of (?)‐pinellic acid with (9S,12S,13S)‐configuration and its (9R,12S,13S)‐diastereoisomer was achieved in high overall yields from a common intermediate derived from (+)‐L ‐diethyl tartrate.     

Sex Pheromone of Chilo Suppressalis: Efficient Syntheses of (Z)-11-Hexadecenal, (Z)-13-Octadecenal And (Z)-9-Hexadecenal

The constituents of the sex attractant pheromone of Chilo suppressalis: (Z)-11-Hexedecenal 1, (Z)-13-octadecenenal 2 and (Z)-9-Hexadecenal 3 have been synthesized as their ethylene acetals 19, 15 and 13, in six steps from easily available compounds. The synthetic methodology can be applied to preparative scale.     

A Convenient Synthesis of (1 1E, 13E)-11, 13-Hexadecadienal and (11Z, 13E)-Hexadecadienal

A simple method for synthesizing (11E, 13E)-11, 13-hexadecadienal 7, a component of the female sex pheromone of cabbage webworm, and its geometrical isomer (11Z, 13E)-11, 13-hexadecadienal 8 is described.     

Synthesis of (+)-2R,3R,11R,12R- and (−)-2S,3S,11S,12S-tetraphenyl-18-crown-6

The synthesis of the title crown ethers starting from optically active hydrobenzoins is described. R(+)-1,in CDCl₃ ,preferentially extracts R(+)-phenylglycine methyl ester hydroperchlorate from an aqueous solution of the racemate with a chiral recognition factor of 1.5 as shown by nmr measurements.