78037-77-1

Upstream product

• 542-92-7 cyclopenta-1,3-diene 
• 78037-74-8 methyl (E)-4,5,6,7-tetra-O-acetyl-2,3-dideoxy-L-arabino-hept-2-enonate 
• 65371-70-2 methyl 2,3-dideoxy-4,5:6,7-di-O-isopropylidene-D-arabino-hept-2-enonate 
• 109005-04-1 bis((1R,2S,5R)-2-isopropyl-5-methylcyclohexyl) (1R,2S,3S,4S)-bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylate 
• 929108-82-7 (1S,2S,3S,4R)-Bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid bis-((R)-1-anthracen-9-yl-2,2,2-trifluoro-ethyl) ester 
• 114473-51-7 C₂₅H₃₄O₆ 
• 129-64-6 3,6-endomethylene-1,2,3,6-tetrahydrophthalic anhydride 
• 114473-52-8 {(1R,2S,3S,4S)-3-[(4R,5R)-5-((1R,2R,3R,4S)-3-Hydroxymethyl-bicyclo[2.2.1]hept-5-en-2-yl)-2,2-dimethyl-[1,3]dioxolan-4-yl]-bicyclo[2.2.1]hept-5-en-2-yl}-methanol 
• 6289-62-9 Acetic acid (1S,2R,3R,4R)-3-acetoxymethyl-bicyclo[2.2.1]hept-5-en-2-ylmethyl ester 
• 162362-11-0 (1S,2R,3S,4R)-Bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid mono-((S)-1-phenyl-ethyl) ester 
• 162489-30-7 (1S,2S,3S,4R)-Bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid 2-tert-butyl ester 3-((S)-1-phenyl-ethyl) ester 

Downstream Products

• 70052-79-8 (2S,3S)-2,3-bis(p-tolylsulfonyloxymethyl)bicyclo<2.2.1>heptane 
• 99891-77-7 Acetic acid (4aR,6S,7R,7aS)-7-methyl-3-oxo-octahydro-cyclopenta[c]pyran-6-yl ester 
• 99946-04-0 isoboonein 
• 2434-86-8 Methanesulfonic acid (2R,3R)-3-methanesulfonyloxymethyl-bicyclo[2.2.1]hept-5-en-2-ylmethyl ester 

Relevant academic research and scientific papers

Stereochemical Versatility in Synthesis of Substituted Cycloalkanes from Acyclic Unsaturated Sugars

Acyclic unsaturated sugars obtained by Wittig extension of aldehydo arabinose precursors undergo stereoselective Diels-Alder addition of cyclopentadiene, permitting isolation of a single, crystalline, optically pure norbornene adduct whose stereochemistry may be controlled by the enantiomeric form of the sugar used and the conditions of the cycloaddition reaction.

Enantioselective Construction of Modular and Asymmetric Baskets

The precise positioning of functional groups about the inner space of abiotic hosts is a challenging task and of interest for developing more effective receptors and catalysts akin to those found in nature. To address it, we herein report a synthetic methodology for preparing basket-like cavitands comprised of three different aromatics as side arms with orthogonal esters at the rim for further functionalization. First, enantioenriched A (borochloronorbornene), B (iodobromonorbornene), and C (boronorbornene) building blocks were obtained by stereoselective syntheses. Second, consecutive A-to-B and then AB-to-C Suzuki–Miyaura (SM) couplings were optimized to give enantioenriched ABC cavitand as the principal product. The robust synthetic protocol allowed us to prepare (a) an enantioenriched basket with three benzene sides and each holding either tBu, Et, or Me esters, (b) both enantiomers of a so-called “spiral staircase” basket with benzene, naphthalene, and anthracene groups surrounding the inner space, and (c) a photo-responsive basket bearing one anthracene and two benzene arms.

Stereo- A nd regioselective synthesis of molecular baskets

We describe a stereoselective method for obtaining multigram quantities of molecular basket 1syn in overall 11% yield, using inexpensive cyclopentadiene and diethyl fumarate as starting materials. First, an asymmetric synthesis of enantioenriched bromo(trimethylstannyl)alkene (-)-8 was accomplished by the stereoselective bromination of dibromonorbornene (+)-4 guided by anchimeric assistance and subsequent syn-exo-elimination of tetrabromonorbornane (-)-5a as the key steps. Subsequent Cu(I)-catalyzed cyclotrimerization of (-)-8 was optimized to give 1syn/anti in 85% yield and 1:1 ratio of diastereomers. Importantly, the results of our mechanistic experiments were in line with the cyclotrimerization occurring in a chain-type fashion with racemization of a Cu(I) homochiral dimeric intermediate, reducing the stereoselectivity of the transformation. Enabled by more facile access to molecular baskets of type 1syn, a range of recognition studies can now be completed for producing novel supramolecular catalysts, organophosphorus scavengers, and nanostructured materials.

A simple method for resolution of endo-/exo-monoesters of trans-norborn-5-ene-2,3-dicarboxylic acids into their enantiomers

Separation of optical isomers obtainable from trans-norborn-5-ene-2,3-dicarboxylic acid methyl and tert-butyl monoesters was performed by crystallization of the respective salts prepared with (R)- and (S)-1-phenylethylamine. Starting from racemic endo-monomethyl ester of trans-norborn-5-ene-2,3-dicarboxylic acid, prepared by partial hydrolysis of the cyclopentadiene-dimethyl fumarate adduct, the corresponding (2R, 3R)-endo-monoester was isolated in 97% enantiomeric excess (ee) yield after seven repeated crystallizations from tetrachloromethane. Starting from exo-mono-tert-butyl ester of the same acid, prepared by alcoholysis of the cyclopentadiene-maleic anhydride adduct followed by isomerization, (2R, 3R)-exo-monoester was isolated in >98% ee yield after four repeated crystallizations from ethanol. Crystallization of the acids from the mother liquor yielded products with inverse stereochemical configuration.

Bioisostere of valtrate, anti-HIV principle by inhibition for nuclear export of Rev

Rational design by the MO calculation disclosed 5,6-dihydrovaltrate (2) as the bioisostere of valtrate (1), the Rev-export inhibitor with anti-HIV activity. The synthesis of 2 was accomplished by ingenious use of asymmetric Diels-Alder reaction and stereoselective epoxidation associated with the adjacent hydroxyl group. Because of similar biological potency to 1, the analog 2 should be recognized as a promising scaffold for new anti-HIV agents with an unprecedented mechanism of action, inhibition for nuclear export of Rev protein, in the conventional remedy.

[4 + 2] Cycloaddition reactions catalyzed by a chiral oxazaborolidinium cation. Reaction rates and diastereo-, regio-, and enantioselectivity depend on whether both bonds are formed simultaneously

chemical equation presented The reaction rates and products in enantioselective Diels-Alder reactions with a range of dienophiles correlate with the expected degree of concertedness of bond formation in the transition state.

Di-2,2,2-trifluoro-1-(9-anthryl)ethyl fumarate, an easy starting point for the enantioselective preparation of trans-cyclohexene-4,5-dicarboxylate derivatives by Diels-Alder reaction

Di-2,2,2-trifluoro-1-(9-anthryl)ethyl fumarate has been synthesized from fumaric acid and enantiopure Pirkle alcohol. The Diels-Alder reaction with different dienes employing different reaction conditions was assayed, with high diastereomeric excesses obtained. The structure and geometry of the cycloadducts was analyzed by NMR, molecular mechanics and X-ray diffraction. Hydrolysis made it possible to obtain the enantioenriched trans-cyclohexene-4,5-dicarboxylate derivatives and allow us to recover chiral auxiliary.

Influence of solvent polarity on the stereoselectivity of the uncatalyzed [4 + 2] cycloaddition of cyclopentadiene to an N,N′-fumaroyl bis-(six-membered ring [(2R)-10a-homobornane-10a,2-sultam])

A new six-membered ring (2R)-bomane-10a,2-sultam was tested as chiral auxiliary for the [4 + 2] cycloaddition of cyclopentadiene to the bis-fumaroyl derivative (-)-lf and shows under chelating conditions similar complete selectivity to Oppolzer's sultam. Inversion of the π-face selectivity is nevertheless observed under uncatalyzed conditions under the influence of solvent polarity, varying from 82% de for the (2R,3R) cycloadduct 2f in trifluoroethanol to 70% de in favour of the (2S,3S) diastereoisomer in hexane as solvent. A predictive linear correlation is observed between the stereoselectivity and the solvent parameters according to the Abboud-Abraham-Kamlet-Taft model. PM3 calculations allowed a rationalization of these results based on the transition-state dipole moment. Illustrated by an x-ray analysis of cycloadduct (2S,3S)-2f, the main structural differences and influences in terms of steric and stereoelectronic factors are discussed by comparison of the five- versus six-membered ring homologues. Copyright

Stereoselectivity in the cycloaddition of cyclopentadiene to N-fumaroyl-[2R,S(R)]-bornane-10,2-sulfinamide monomethyl ester

The cyclic [2R,S(R)]-bornane-10,2-sulfinamide (-)-2b, an analogue of Oppolzer's camphor-derived sultam (-)-2a, was synthesized by reduction of the known N-alkylidenesulfinamide (+)-1b with NaBH4. The uncatalyzed [4 + 2] cycloaddition of cyclopentadiene to the methyl ester (-)-3b of the N-fumaroylsulfinamide, obtained from (-)-2b, proceeds with lower endo and π-facial selectivity as compared to dienophiles (-)-3a, c. In contrast to these latter, the diastereoselectivity is reversed either in apolar CCl4 or in the presence of TiCl4. This inversion is explained by a competitive C(α)-si addition on the reactive anti-s-trans conformer.

THERMAL AND CATALYTIC DIELS-ALDER REACTIONS BETWEEN (2E)-4,5,6-TRI-O-ACETYL-2,3-DIDEOXY-ALDEHYDO-D-ERYTHRO-HEX-2-ENOSE AND CYCLOPENTADIENE

Thermal and catalytic reactions between (2E)-4,5,6-tri-2,3-dideoxy-aldehydo-D-erythro-hex-2-enose (1) and cyclopentadiene 1ed, in each case, to the four stereoisomeric 5-formyl-6-(1,2,3-tri-O-acetyl-D-erythro-triol-1-yl)bicyclohept-2-enes (2-5).The role of the catalysts is discussed, and the face selectivity is rationalized in terms of both steric and electrostatic arguments.Upon subsequent sodium borohydride reduction, iodination, and zinc reduction, the adducts 2-5 were converted to their respective primary alcohols 6-9, that could be separated by column chromatography.Sequential basic deacetylation, oxidative cleavage of the sugar side-chain with sodium metaperiodate, and reduction with sodium borohydride, yielded the previously known (5R,6R)- or(5S,6S)-bis(hydroxymethyl)norbornene-diols 12 or 13, thus establishing the C-5 and C-6 absolute configurations of their synthetic precursors.