Synthesis of spirocyclopente-dione anthracene adduct, precursor of the cyclopentenone prostagladins via ring-closing metathesis reaction

A synthesis of the spirocyclopente-dione anthracene adduct, a precursor of the cyclopentenone prostaglandins has been reported. The synthesis involved a Diels-Alder reaction of anthracene and dimethyl fumarate to afford 3 followed by reduction, oxidation and esterification reactions to provide methyl ester anthracene adduct 8, which further converted to the the allylic alcohol (12). Then, Ring-Closing Metathesis (RCM) reaction afforded the cyclopentenol anthracene adduct, which after oxidation provided the spirocyclopente-dione anthracene adduct in good yields

Stereoselective synthesis of α-methylenecyclopentenones via a Diels-Alder/retro-Diels-Alder protocol

A new procedure for the stereoselective synthesis of cross-conjugated dienones is reported. This method makes use of the Diels–Alder adduct of anthracene and dimethyl fumarate, a precursor to a spirocyclopent-2-enone anthracene adduct as the key intermediate. The addition of propyllithium or octyllithium to the key intermediate followed by a retro-Diels–Alder reaction furnished α-methylenecyclopentenones bearing a γ-propyl or γ-octyl side chain, respectively, in moderate yields and as single geometric isomers

Synthesis of Spirocyclopente-Dione Anthracene Adduct, Precursor of the Cyclopentenone Prostagladins Via Ring-Closing Metathesis Reaction

Abstract: A synthesis of the spirocyclopente-dione anthracene adduct, a precursor of the cyclopentenone prostaglandins has been reported. The synthesis involved a Diels-Alder reaction of anthracene and dimethyl fumarate to afford 3 followed by reduction, oxidation and esterification reactions to provide methyl ester anthracene adduct 8, which further converted to the the allylic alcohol (12). Then, Ring-Closing Metathesis (RCM) reaction afforded the cyclopentenol anthracene adduct, which after oxidation provided the spirocyclopente-dione anthracene adduct in good yields

Studies of stereo-selective cyclo-additions and transformations of substituted 2-cyclopenten-1-one with chiral anthracene templates

The chiral (S)-9-(1-methoxyethyl), (R)-9-(1,2-dimethoxyethyl) and 9-(1R, 2R)-(1,2-dimethoxypropyl) anthracenes were synthesised and used for the thermal Diels-Alder reaction with cyclopentene-3,5-dione. Unlike the maleic anhydride and N-substituted malemides, the cyclo-adducts were obtained with high regio-selectivity as a single diastereomer. The X-ray structure of the cyclo-adduct showed an enol form but the 13C NMR showed resonances for two cyclopentanone carbonyl groups suggesting the solution structure is in the diketone form. Stereo-controlled studies using organomagnesium additions to the carbonyl groups resulted in hydrolytic cleavage of the enol ether and elimination of water to give β-alkylketone anthracene adducts. These were unsuccessful in preparing chiral cyclopentenone core structures

Stereoselective synthesis of α-methylenecyclopentenones via a Diels-Alder/retro-Diels-Alder protocol

A new procedure for the stereoselective synthesis of cross-conjugated dienones is reported. This method makes use of the Diels-Alder adduct of anthracene and dimethyl fumarate, a precursor to a spirocyclopent-2-enone anthracene adduct as the key intermed