56324-31-3

Upstream product

• 470-40-6 thujopsene 
• 603137-30-0 3-Methyl-6-((S)-1,2,2-trimethyl-cyclopentyl)-cyclohexa-1,4-diene 
• 51941-57-2 1,2-Dimethyl-2-hydroxymethyl-1-p-tolylcyclopentane 
• 51941-58-3 1,2-Dimethyl-2-formyl-1-p-tolylcyclopentane 
• 24493-43-4 (+)-β-bazzanene 
• 54750-40-2 1-(1,2-dimethylcyclopent-2-en-1-yl)-4-methylbenzene 
• 544-97-8 dimethyl zinc(II) 
• 121469-00-9 (-)-(S)-2-methyl-2-(4-methylphenyl)cyclopentanone 
• 35739-70-9 dimethyldichlorotitanium(IV) 
• 4608-41-7 2-methyl-2-(4-methylphenyl)cyclopentanone 
• 35340-45-5 Cl₂Ti(CH₃) 
• 119305-94-1 cis-1,2,3,3a,4,9b-Hexahydro-3a,7,9b-trimethyl-cyclopentabenzothiopyran 
• 138100-37-5 3,3-dimethyl-6-iodo-2-(4-methylphenyl)-1-hexene 
• 51941-58-3 1,2-dimethyl-2-p-tolylcyclopentane-1-carbaldehyde 

Downstream Products

• 934737-75-4 (R)-2-Nitro-cuparen 
• 509-02-4 Cuparensaeure 
• 52528-92-4 N-Acetyl-N-[2-methyl-5-((R)-1,2,2-trimethyl-cyclopentyl)-phenyl]-acetamide 
• 52528-93-5 (R)-2-Benzoyloxycuparen 
• 38510-59-7 (R)-2-Acetoxycuparen 

Relevant academic research and scientific papers

Catalytic asymmetric total syntheses of (+)-α-cuparenone, (+)-cuparene and (+)-herbertene

A general catalytic asymmetric route to either enantiomers of sesquiterpenes, cuparenes (1–2) and herbertenes (8–9) is disclosed from commercially available 3-methyl cyclopenten-2-one. Following a catalytic enantioselective addition of arylboronic acids to enone 15, compounds 14a-b with all carbon quaternary stereocenters are synthesized in up to 90percent ee in the presence of Pd(II)-PyOx (pyridine oxazoline). Compounds 14a-b are used as precursors for the asymmetric total syntheses of (+)-cuparene (1a) (35percent overall yield in 3 steps), α-(+)-cuparenone (1b) (56percent overall yield in 2 steps), and (+)-herbertene (8a) (34percent overall yield in 3 steps).

New Strategy for Forging Contiguous Quaternary Carbon Centers via H 2 O 2 -Mediated Ring Contraction

Stereospecific construction of contiguous quaternary carbon centers constitutes a major challenge in natural product synthesis. A general protocol that enables stereospecific construction of all stereoisomers of such a moiety remains elusive. In this article, we will discuss the oxidative ring contraction of all-substituted cyclic α-formyl ketones mediated by H 2 O 2, which provides a facile access to the stereospecific construction of contiguous quaternary carbon centers.

Stereospecific Construction of Contiguous Quaternary All-Carbon Centers by Oxidative Ring Contraction

Oxidative ring contraction of cyclic α-formyl ketones was facilitated by the action of H2O2under operationally simple and environmentally benign reaction conditions. The process was highly regioselective and enables stereospecific construction of contiguous quaternary all-carbon centers from stereodefined all-substituted all-cyclic ketones. The asymmetric syntheses of (+)-cuparene and (+)-tochuinyl acetate were also successively achieved by taking advantage of this novel protocol.

Asymmetric total synthesis of (R)-α-cuparenone, (S)-cuparene and formal synthesis of (R)-β-cuparenone through Meinwald rearrangement and ring closing metathesis (RCM) reaction

Asymmetric synthesis of enantiopure cuparenoid sesquiterpenes (R)-α-cuparenone, (S)-cuparene and a formal synthesis of (R)-β-cuparenone was presented in this article. Meinwald rearrangement of an enantiopure trisubstituted 2,3-epoxy alcohol derivative was

(5,6-Dihydro-1,4-dithiin-2-yl)methanol as a Versatile Allyl-Cation Equivalent in (3+2) Cycloaddition Reactions

The title heterocyclic alcohol readily generates a sulfur-substituted allylic cation upon simple treatment with a protic acid, thus facilitating a synthetically useful stepwise (3+2) cycloaddition reaction pathway with a range of conjugated-olefin-type substrates. The introduction of an allyl fragment in this way provided rapid access to a variety of cyclopentanoid scaffolds. The cyclic nature of the cation precursor alcohol was shown to be instrumental for efficient cycloaddition reactions to take place, thus indicating an attractive strategy for controlling the reactivity of heteroatom-substituted allyl cations. The formal cycloaddition reaction is highly regio- and stereoselective and was also used for a short total synthesis of the natural product cuparene in racemic form through a cycloaddition–hydrodesulfurization sequence.

RCM-based approach to (±)-cuparene

An efficient approach to the aromatic sesquiterpene cuparene has been described starting from the readily available β-ionone and employing a combination of epoxide rearrangement-based ring-contraction and ring-closing metathesis reactions as key steps. Copyright Taylor & Francis Group, LLC.

Photomediated asymmetric synthesis of (-)-cuparene.

Generation of a benzylic quaternary stereocentre via the photomediated cyclisation of a chiral alpha-(aminobutyl)styrene followed by a microwave-assisted Cope elimination has led to a total synthesis of the sesquiterpene (-)-cuparene.

Convenient route to enantiopure aryl cyclopentanes via Diels-Alder reaction of asymmetric dienes. Total synthesis of (+)-herbertene and (+)-cuparene

A general route for the synthesis of highly substituted aryl cyclopentanes has been developed involving Diels-Alder reaction of asymmetric dienes prepared from (+)-camphoric acid followed by aromatization of the resulting cyclohexene derivatives. Employing this protocol enantiospecific synthesis of (+)-herbertene and (+)-cuparene has been accomplished.

Use of aromatic radical-anions in the absence of THF. Tandem formation and cyclization of benzyllithiums derived from the attack of homo- and bishomoallyllithiums on α-methylstyrenes: Two-pot synthesis of cuparene

When a homo- or bishomoallyllithium, generated by reductive lithiation of the corresponding phenyl thioether by the radical anion lithium 1-(dimethylamino)naphthalenide (LDMAN), is added to α-methylstyrene, a tandem addition/cyclization to a phenyl-substituted five- or six-membered-ring occurs. The yields are compromised by polymerization of the α-methylstyrene, a process favored by tetrahydrofuran (THF), the solvent used to generate lithium aromatic radical anions. Thus, a new method of generating LDMAN (unsuccessful for other common radical anions) in the absence of THF has been developed. The radical anion can be generated and the reductive lithiation performed in dimethyl ether at -70 °C. After the addition of diethyl ether or other solvent, and evaporation of the dimethyl ether in vacuo, the α-methylstyrene is added and the solution is warmed to -30 °C. When the unsaturated alkyllithium is primary, no adduct forms in THF due to polymerization of the α-methylstyrene, but moderate yields are attained in a solvent containing mainly hexanes. It was also found that the cyclized organolithiums, which would have become protonated in the presence of THF, can be captured by an electrophile, even at ambient temperature. A two-pot synthesis, the most efficient reported, of the sesquiterpene (±)-cuparene in 46% yield, using this technology is reported.