- Intramolecular Diels-Alder reactions from trichloro-1,2,4-triazine and 1,5- And 1,6-dienes
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The initial dihydropyridines from Diels-Alder addition of dienes to trichloro-1,2,4-triazine, and loss of N2, undergo intramolecular addition with hexa-1,5-diene and cyclo-octa-1,5-diene, also [1,5]H sigmatropic shift with diallyl ether, and [1,5]H shift and partial aromatisation with cyclododeca-1,5,9-triene.
- Barlow, Michael G.,Sibous, Lakhdar,Tipping, Anthony E.
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- PREPARATION OF PHANTASMIDINE AND ANALOGUES THEREOF
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Described are methods of synthesizing phantasmidine and analogues thereof from commercially available starting materials. The compounds are useful as pharmacological probes and potential lead compounds for the development of selective nicotinic receptor therapeutics.
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Page/Page column 28-29
(2012/06/30)
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- Synthesis of phantasmidine
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Reaction of 6-chloro-2-fluoro-3-pyridineacetamide with 1,2- bis(trimethylsilyloxy)cyclobutene in ether saturated with hydrogen chloride afforded the keto amide in 85% yield. In the key step, treatment of the keto amide with aqueous KOH in t-BuOH resulted in a tandem intramolecular aldol reaction-intramolecular nucleophilic aromatic substitution sequence to give the tetracylic lactam in 46% yield. Reduction of the lactam with BH3 in THF gave phantasmidine in 67% yield.
- Zhou, Quan,Snider, Barry B.
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supporting information; experimental part
p. 526 - 529
(2011/03/23)
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- Tricyclic vasopressin agonists
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This invention relates to new compounds selected from those of the general formula (I), or a pharmaceutically acceptable salt, ester or prodrug form thereof: wherein D, E and G are N or CH, which serve as vasopressin agonists and are useful in treating disorders such as diabetes insipidus, nocturnal enuresis, nocturia, urinary incontinence, bleeding and coagulation disorders, and the inability to temporarily delay urination and pharmaceutical compositions and methods for same.
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- Diels-Alder reactions of trichloro-1,2,4-triazine: Intramolecular additions with 1,5 and 1,6 dienes
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Trichloro-1,2,4-triazine reacts with cycloheptene and cyclododecene to give the 2,6-dichloropyridine derivatives 6 and 7 via an intermediate dihydropyridine formed by Diels-Alder addition and loss of N2, and with cyclopenta-1,3-diene and indene by addition of a second molecule of alkene to the intermediate dihydropyridine. Bicyclo[2.2.1]hepta-2,5-diene and quadricyclane give mainly 2,3,6-trichloropyridine by loss of cyclopentadiene from the intermediate dihydropyridine. With hexa-1,5-diene, the dihydropyridine is trapped by an intramolecular Diels-Alder reaction, forming tricyclic compounds 17 and 18. With diallyl ether, the dihydropyridine partly undergoes intramolecular cycloaddition to give 23 and partly [1,5]-sigmatropic shift of hydrogen before intramolecular cycloaddition to give 25. With cyclododeca1,5,9-triene formation of pyridine derivatives is incomplete and the immediate precursor can be trapped with water.
- Barlow, Michael G.,Sibous, Lakhdar,Suliman, Nadia N. E.,Tipping, Anthony E.
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p. 519 - 524
(2007/10/03)
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