Fourteen-membered Ring Research Articles

Reactions of αω-dodecatrienediylnickel with dimethyl acetylenedicarboxylate and methyl propiolate

The reaction of αω-dodecatrienediylnickel with dimethyl acetylenedicarboxylate at 0 °C yields approximately equal amounts of twelve- and fourteen-membered ring products, whereas, at –78 °C, 80% of the product has the larger ring. The reaction of αω-dodecatrienediylnickel with methyl propiolate yields exclusively methyl 12-vinylcyclododeca-1,4,8-trienecarboxylate. A similar insertion reaction of dimethyl acetylenedicarboxylate into a bis(η-allyl)-nickel complex, derived from αω-dodecatrienediylnickel and allene, has been shown to give a reasonable yield of dimethyl 14-methylenecyclohexadeca-1,4,8,12-tetraene-1,2-dicarboxylate.

Diazepines. Part 23. The formation and structure of 1,5-diaza- and 5-aza-1-oxa-pentadienium salts and their use in the preparation of 2,3-dihydro-1,4-diazepinium salts

1,5-Diaza- and 5-aza-1-oxa-pentadienium salts serve as excellent precursors for the preparation of 2,3-dihydro-1,4-diazepinium salts, including some that are not readily obtained by other methods. Sometimes imidazolinium rings are formed instead of or in addition to the desired product. The preparation of these precursors is discussed. The shape of diazapentadienium salts is considered, based on spectroscopic evidence. The formation of fourteen-membered rings from azaoxapentadienium salts is also mentioned.

Amino-acids and peptides. Part XVII. Synthesis of cyclo-[(O-t-butyl)-L-seryl-β-alanyl-glycyl-(O-methyl)-L-β-aspartyl], and observations on the rearrangement of β-aspartyl peptide esters

The title fourteen-membered ring system was synthesised by cyclisation of the corresponding linear tetrapeptide p-nitrophenyl ester. When ring closure of the related tetrapeptide with terminal β-alanine and glycine residues was attempted, no cyclic peptide was formed; the aspartyl residue rearranged remarkably readily from β- to α-. The synthesis of several peptides containing β-aspartyl residues established that the sequence O-methyl-L-β-aspartyl(O-t-butyl)-L-seryl-β-alanyl particularly favoured this rearrangement.

Structures and conformations of the fourteen-membered ring diterpene ovatodiolide and its acid cyclization product: nuclear Overhauser effect studies in solution and X-ray crystal structure analyses of ovatodiolide and ovatodiolic acid

The conformation and relative stereochemistry of ovatodiolide (1), a fourteen-membered ring diterpene dilactone isolated from Anisomeles ovata, have been elucidated by 1H n.m.r. spectroscopy including intramolecular nuclear Overhauser effect measurements. The structure of ovatodiolic acid (3), an acid cyclization product of (1) has also been investigated. Single-crystal X-ray analyses have confirmed the structural and stereochemical assignments of (1) and (3) both of which crystallize in the orthorhombic system, space group P212121, with a= 12.798(8), b= 13.255(8), c= 10.950(8)A, Z= 4, for (1), and a= 12.994(8), b= 14.435(9), c= 9.432(8)A, Z= 4, for (3). The crystal structures were solved by direct non-centrosymmetric phase-determining procedures and atomic parameters refined from diffractometer data by full-matrix least-squares calculations to R 0.071 [1 280 reflections (1)] and 0.074 [1 399 reflections, (3)]. The trisubstituted trans double bonds in (3) are distinctly distorted from planarity.

Synthesis of (+-)-cembrene, a fourteen-membered ring diterpene

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis of (+-)-cembrene, a fourteen-membered ring diterpeneW. G. Dauben, G. H. Beasley, M. D. Broadhurst, B. Muller, D. J. Peppard, P. Pesnelle, and C. SuterCite this: J. Am. Chem. Soc. 1975, 97, 17, 4973–4980Publication Date (Print):August 1, 1975Publication History Published online1 May 2002Published inissue 1 August 1975https://doi.org/10.1021/ja00850a035RIGHTS & PERMISSIONSArticle Views439Altmetric-Citations36LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1 MB) Get e-Alerts Get e-Alerts

The crystal structure of mauritin-A, C32H41N5O5

Abstract Mauritin-A is a cyclic peptide-alkaloid with a fourteen-membered ring system. Since UV spectra indicated a strong tension within the molecule a crystal-structure analysis was undertaken by means of single-crystal diffractometry. The space group is P21 with a = 13.968 Å, b = 9.577 Å, c = 13.538 Å and β = 114.61°. The structure was solved by use of direct methods. The molecular structure found confirms completely the molecular model established by physical and chemical methods as well as the tension within the central ring system.

Insertion of dimethyl acetylenedicarboxylate into α,ω-dodecatrienediylnickel

The reaction of dimethyl acetylenedicarboxylate with α,ω-dodecatrienediylnickel at 0 °C yields approximately equal amounts of twelve- and fourteen-membered ring products, whereas, at –78 °C, 80% of the product has the larger ring; subsequent reactions yielded a series of musk compounds with differing odours.

Studies on 1-Azabicyclo Compounds. XVIII. Synthesis of Fourteenmembered Ring Diamine, 1, 8-Dimethyl-1, 8-diazacyclotetradecane, and Related Compounds from Perhydrodipyrido [1, 2-a : 1', 2'-d]-pyrazine via Ten-membered Ring Diamine, 2-Methyl-perhydro-2H-pyrido [2, 1-c]-2, 9-diazecine

Oxidation of the anti- and syn-diamine (IX and X) with mercuric acetate gave the enaminolactam (XII). Treatment of the methiodides (XIII, XVIII, and XIX) with lithium in liquid ammonia afforded the ten-membered ring aminolactam (XX) in an excellent yield, which was reduced to the ten-membered ring diamine (XXI). Hofmann degradation of the carbamate (XXIII) derived from XXI provided the fourteen-membered ring aminocarbamate (XXVII) and the oxazolidone (XXVIII), which were converted to the fourteen-membered ring diamine (XXX) and the hydroxydiamine (XXXI), respectively.

Amino-acids and peptides. 13. Syntheses of two fourteen-membered ring cyclotetrapeptides.

The fourteen-membered ring cyclotetrapeptides cyclo-(β-alanylglycyl-β-D-aspartylglycyl) methyl ester and cyclo-[β-alanylglycyl-L-(α-amino)-β-alanylglycyl] have been synthesised through the cyclisation of the corresponding linear tetrapeptides with o-phenylene chlorophosphite.

The reaction between αβ-unsaturated ketones and ethylenediamine

Ethylenediamine reacts with different αβ-unsaturated ketones to give open chain adducts, or seven-or fourteen-membered rings.

Thunbergol, a New Macrocyclic Diterpene Alcohol.

Abstract : Thunbergol is a monocyclic diterpene alcohol which occurs in the oleoresin of Douglas fir, Pseudotsuga menziesii (Mirb.) Franco. Spectroscopic studies and dehydration to thunbergene (cembrene) established the structure (1-isopropyl-4,8,12-trimethyl-2,7,11-cycloteradecatriene-4-o1) of thunbergol which is thus a new member of the diterpene series containing a fourteen-membered ring. The possible relationships between thunbergol and cembrol previously isolated from Pinus sibirica R. Mayr. are discussed. (Author)

Unsaturated Macrocyclic compounds—LII : The synthesis of 1,8-diethynylinaphthalene and its oxidation to a conjugated fourteen-membered ring system

A seven step synthesis of 1,8-diethynylnaphthalene (IX) from naphthalic anhydride (I) is described. Oxidation of IX with oxygen, cuprous chloride and ammonium chloride gave the very unstable “cyclic dimer” (XX), containing a conjugated 14-membered ring.

Electrophilic Substitution of Aromatic Fourteen-Membered Ring Cyclic Conjugated Systems

Electrophilic Substitution of Aromatic Fourteen-Membered Ring Cyclic Conjugated Systems