140224-89-1

Upstream product

• 251959-53-2 (2R,3S,5R,6R)-3-((1E,3E)-Hepta-1,3-dienyl)-2-hydroxymethyl-5,6-bis-trimethylsilanyloxy-cyclohexanone 
• 50-00-0 formaldehyd 
• 764-58-9 (E)-hept-3-ene-1-yne 
• 251959-52-1 (5R,6R)-bis-trimethylsiloxy-2-cyclohexenone 
• 93542-63-3 6-hepta-1,3-dienyl-5-hydroxymethyl-2,2-dimethylhexahydrobenzo[1,3]dioxol-4-one 
• 1166841-84-4 (2R,3R,5S,6R)-2,3-bis-(tert-butyl-dimethyl-silyloxy)-5-((1E,3E)-hepta-1,3-dienyl)-4-hydroxymethyl-cyclohexanone 
• 64-19-7 acetic acid 
• 66124-67-2 t-5,t-6-dihydroxy-5,6-di-O-isopropylidene-c-3-<(1E,3E)-1,3-heptadienyl>-c-2-trityloxymethyl-r-1-cyclohexanol 
• 61518-48-7 dimethyl c-3-hydroxy-4-cyclohexen-r-1,c-2-dicarboxylate 
• 66124-58-1 1,3,3a,4,7,7a-hexahydro-1,3-dioxoisobenzofuran-4-yl acetate 
• 75758-53-1 t-5,t-6-dihydroxy-5,6-di-O-isopropylidene-c-3-<(1E,3E)-1,3-heptadienyl>-r-2-trityloxymethyl-1-cyclohexanone 
• 66354-38-9 c-3-acetoxy-c-2-acetoxymethyl-t-4,t-5-dihydroxy-4,5-di-O-isopropylide-r-1-<(1E,3E)-1,3-heptadienyl>cyclohexane 
• 66124-64-9 5,6-di-O-isopropylidene-3-acetoxy-8-hydroxymethyl-2-oxabicyclo<3.2.1>heptane 
• 66169-83-3 c-2-acetoxymethyl-t-5,t-6-dihydroxy-5,6-di-O-isopropylidene-c-3-<(1E,3E)-1,3-heptadienyl>-r-1-cyclohexanol 

Downstream Products

• 1612143-72-2 {(1R,3R,4R,6S)-3-(acetyloxy)-6-[(1E,3E)-hepta-1,3-dien-1-yl]-4-hydroxy-2-oxocyclohexyl}methyl acetate 

Relevant academic research and scientific papers

Organocatalytic asymmetric Robinson annulation of α,β- unsaturated aldehydes: Applications to the total synthesis of (+)-palitantin

(Chemical Equation Presented) The highly enantioselective organocatalytic Robinson annulation of α,β-unsaturated aldehydes was achieved, catalyzed by L-proline and trialkylamines and providing the formal [4 + 2] cycloaddition adducts. Additionally, in some examples in the catalysis with diarylpyrrolinol silyl ethers, the reactions afforded the [4 + 2] adducts with high enantioselectivity (>99.5% ee). The structure of the adduct, obtained from the reaction of 3-methylbut-2-enal and (E)-3-(2-nitrophenyl)acrylaldehyde, was confirmed by X-ray analysis. The absolute configurations of some [4 + 2] cycloadducts were investigated, and the methodology was applied in the synthesis of (+)-palitantin.

Asymmetric synthesis of palitantin by an enzymatic and organocatalytic approach

The natural enantiomer of the fungal metabolite (+)-palitantin has been synthesized by adopting a chemoenzymatic and organocatalytic approach. Lipase catalyzed kinetic resolution, Sharpless asymmetric dihydroxylation and organocatalytic asymmetric hydroxy

Asymmetric synthesis of palitantin from the (5R)-tert-butyldimenthylsiloxy-2-cyclohexenone

(+)-Palitantin (2) has been synthesized in 25% overall yield from the (5R)-tert-butyldimethylsiloxy-2-cyclohexenone [(R)-1] where a remarkable diastereoselective cat. OsO4 cis-dihydroxylation of (R)-1 furnished the precursor of the optically pure (5R,6R)-bis-trimethylsiloxy 2-cyclohexenone (7) which underwent highly selectively the 1,4-addition reaction of the 1,3-heptadienyl cyanocuprate to give, after trapping of the corresponding copper enolate with formaldehyde, the target compound.

SYNTHESIS OF (+)-PALITANTIN

(-)-Quinic acid was utilized for the synthesis of (+)-palitantin adopting the chiron approach.Pertinent methodology includes stereocontrolled free-radical deoxygenation, functional group adjustments and an α-keto hydroxymethylation reaction.

THE BIOSYNTHESIS OF FULVIC ACID, A FUNGAL METABOLITE OF HEPTAKETIDE ORIGIN

Analyses of the regiochemistry of acetate incorporation into fulvic acid (2) by Penicillium brefeldianum indicates that the metabolite is biosynthesized via a heptaketide intermediate assembled as a single chain of seven C2 units rather than from two smaller polyketide chains.This information favours a route leading through common C14 intermediates to the three fungal metabolites, citromycetin, fulvic acid and fusarubin.

STEREOSELECTIVE SYNTHESIS OF (+/-)-PALITANTIN

Stereoselective synthesis of (+/-)-palitantin has been completed.