73540-80-4

Upstream product

• 112182-00-0 (2E,4E)-6-Methylheptadiensaeure-ethylester 
• 24502-08-7 (E)-4-methylpent-2-enal 
• 73540-79-1 6-methyl-hepta-2t,4t-dienoic acid methyl ester 

Downstream Products

• 197013-53-9 (1SR,3RS,4RS,6SR)-1-(hydroxymethyl)-6-(2-propyl)bicyclopropane 
• 80595-61-5 (1R,2S,5R)-2-(1-methyl-1-phenylethyl)-5-methylcyclohexyl (E,E,E)-11-methyldodeca-2,7,9-trienoate 
• 80656-20-8 (2Z,7E,9E)-11-Methyl-dodeca-2,7,9-trienoic acid (1R,2S,5R)-5-methyl-2-(1-methyl-1-phenyl-ethyl)-cyclohexyl ester 
• 80595-65-9 (2E,7E,9E)-11-Methyl-dodeca-2,7,9-trienoic acid (1R,5R)-2-isopropyl-5-methyl-cyclohexyl ester 

Relevant academic research and scientific papers

Site-Selective trans-Hydrostannation of 1,3- and 1,n-Diynes: Application to the Total Synthesis of Typhonosides E and F, and a Fluorinated Cerebroside Analogue

Propargyl alcohols are privileged substrates for stereochemically unorthodox trans-hydrostannation reactions catalyzed by [Cp*RuCl]4 (Cp=pentamethylcyclopentadienyl), because an incipient hydrogen bond between the -OH group and the polarized [Ru-Cl] unit assists substrate binding. For this very reason, it is also possible to subject diyne derivatives carrying one -OH group to site-selective stannylation, even if the acetylene units are conjugated and hence, electronically coupled. An unusual temperature dependence was observed in that heating tends to improve site-selectivity, whereas per-stannylation is favored when the reaction is carried out in the cold. This counterintuitive trend can be rationalized based on spectroscopic data; additional support comes from the isolation of the unusual bimetallic complex 11. The bridging fulvene and enynyl ligands in 11 are thought to reflect an interligand redox isomerization process likely triggered by synchronous activation of the 1,3-diyne substrate by two metal centers. The preparative relevance of site-selective trans-hydrostannation is illustrated by the total synthesis of two members of the typhonoside series of glycolipids, which are endowed with neuroprotective properties. Moreover, the preparation of a fluoroalkene sphingosine analogue shows that the tin residue also serves as a versatile handle for late-stage modification of a bioactive target compound.

Asymmetric synthesis of bicyclopropane derivatives

Both syn- and anti-bicyclopropane derivatives have been efficiently prepared with good relative and absolute stereocontrol using reagent controlled asymmetric cyclopropanation reactions. Double Simmons-Smith cyclopropanation of 2,4-dien-1-ols stereoselectively gave the corresponding anti-bicyclopropane derivatives.

Synthesis of functionalized bicycloocta-2,6-dienes by thermal rearrangement of substituted 6-exo-(1-alkenyl)bicyclohex-2-ene systems

Thermolysis of each of the enol silyl ethers 31-35 affords, cleanly and efficiently, the bicyclooctadienes 36-40, respectively.Similarly, thermal rearrangement of the enol silyl ether 50 provides the diene 51.Hydrolysis of 36, 37, and 39, and decar

THERMAL REARRANGEMENT OF DIVINYLCYCLOPROPANE SYSTEMS. PREPARATION OF FUNCTIONALIZED, STEREOCHEMICALLY DEFINED BICYCLIC AND TRICYCLIC PRODUCTS CONTAINING THE BICYCLOOCTANE SKELETON

A study involving the preparation and thermolysis of substituted 6-exo-(1-alkenyl)bicyclohex-2-ene systems (14, 15, 23, 29, 40) shows (a) that C-8 functionalized bicycloocta-2,6-dienes can be prepared readily via this methodology (14 -> 16; 15 -> 17), (b) that the rearrangement reaction is stereospecific even when the 6-(1-alkenyl) group is substituted with a sterically bulky isopropyl group (23 -> 24; 29 -> 30), and (c) that the method can be extended to include the preparation of tricyclic systems (40 -> 41).

Total Synthesis of (+/-)-Dendrobine

A total synthesis of (+/-)-dendrobine is described. (E,E,E)-Triene 9a, available stereoselectively in six steps from methyl 4-(diethylphosphono)crotonate, cyclizes by an intramolecular Diels-Alder reaction to afford 75-83percent of a mixture of four perhydroindanols containing 83percent of endo isomers 8a and 8b.Epimers 8a and 8b were transformed into nitrile 25 by two separate routes, each of which involves epimerization of C4, oxidation, angular methylation, and reductive cyanation.Nitrile 25 served as a precursor of amino ester 3 by two separate routes, the most efficient of which proceeded via bromolactone 40.Epoxidation of the trichloroethylurethane 58 prepared from 3 afforded a mixture of two epoxides, both of which were utilized in the synthesis.The minor epoxide, 59 (38-40percent yields), was transformed into dendrobine via methyl ketodendrobinate 57, while the major epoxide 60 (45-48percent yields) was recycled to 58.Additional strategies for the synthesis of dendrobine from 3 are discussed.