77128-35-9Relevant academic research and scientific papers
Synthesis of (+/-)-Muscopyridine via C-ZIP Ring Enlargement
Hadj-Abo, Ferrid,Hesse, Manfred
, p. 1834 - 1839 (2007/10/02)
Treatment of 4-(1-nitro-2-oxocyclododec-1-yl)butanal (1) and of its methyl derivative 5 with pentylamine in EtOH at room temperature gave the ring-enlarged aminomethylidene derivatives 6 and 7, respectively (Scheme 1).After hydrolysis of the aminomethylidene group in 6 and 7 and deformylation followed by a reductive Nef-type reaction, the macrocyclic diketones 10 and 11, respectively, were obtained.They were transformed by a modified Hantzsch procedure to the title compound (+/-)-muscopyridine (13) and normuscopyridine (12), respectively.
Regio- and Stereoselective Cyclopentannulation with Ketones and Propargyl Alcohol Derivatives. Synthesis of dl-Nootkatone and dl-Muscopyridine
Hiyama, Tamejiro,Shinoda, Masaki,Saimoto, Hiroyuki,Nozaki, Hitosi
, p. 2747 - 2758 (2007/10/02)
A highly regio- and stereoselective five-membered ring annulation involving the acid-treatment of propargyl alcohol dianion adducts of ketones is described.The propargyl alcohol adduct of 2-octanone was converted into 2-methyl-3-pentyl-2-cyclopentenone by treatment with sulfuric acid-methanol (1:1) at 0 deg C.As the major product, 1-methylbicyclodec-6-en-8-one was produced from 2-methylcycloheptanone.Remarkable regioselective cyclopentannulation was observed in 2-methylcyclohexanone and 2,3-dimethylcyclohexanone wherein 1-methyl- and trans-1,2-dimethyl-substituted bicyclonon-5-en-7-one (BNO) are produced, respectively.With 3-butyn-2-ol, 2-methylcyclohexanone was converted into the cis-1,9-dimethyl-substituted BNO. 4-Isopropyl-2-methylcyclohexanone was transformed into an 83-85:17-15 mixture of c-3-isopropyl-r-1,c-9-dimethyl-BNO and its 3-epimer.These results are explained in terms of the conrotatory ring-closure of thermodynamically most favorable hydroxypentadienyl cation intermediates. 3-Methoxycarbonyl-cis-1,9-dimethyl-BNO produced from 4-methoxycarbonyl-2-methylcyclohexanone and 3-butyn-2-ol was successfully transformed into dl-nootkatone by converting the methoxycarbonyl group into isopropenyl of correct stereochemistry followed by ring enlargement.Cyclopentannulation using propargyl alcohol dianion adducts of 2-cycloalkenones is discussed.Annulation takes place regioselectively to give conjugated dienones, e.g., (E)-bicyclopentadeca-1(12),2-dien-13-one from 2-cyclododecenone.This product is led to dl-muscopyridine by conjugate 1,6-addition of methyl group followed by ring expansion and finally by aromatization with hydroxylamine hydrochloride.
A new synthesis of dl-muscopyridine based on the regioselective cyclopentenone annulation
Saimoto, Hiroyuki,Hiyama, Tamejiro,Nozaki, Hitosi
, p. 3897 - 3898 (2007/10/02)
Sulphuric acid catalyzed ring closure of propargyl alcohol dianion adduct of 2-cyclododecenone gives bicyclo[10.3.0]pentadec-1(12),2-dien-13-one. 1,6-Conjugate addition of methyl group followed by ring-expansion and aromatization affords the title compounds.
