Ring opening isocycles

The reactions in Methods A, B and C, which all start from pyrylium salts are analogous to the well-known conversions of 2.4.6-substituted pyrylium salts 27 with ammonia, primary amines, hydrogen sulfide or the anions of CH activated compounds to the corresponding heterocyclic or isocyclic aromatic systems The first step involves addition of the basic phosphine at C-2 (or C-6) to form 2S. Ring-opening, ring-closure and elimination of water are likely steps in the formation of the product 2. [Pg.21]

Potassium/tert-butanolldimethyl sulfoxide-oxygen Isocyclic ring opening of fused thiophene derivs. to carboxylic acids... [Pg.50]

Ring expansion of isocyclics by 1,1-dihalogenocyclopropane ring opening... [Pg.69]

Hydrogen peroxide sodium hydroxide Oxidative cleavage of a,/ -ethyIeneketones Ring opening of isocycles... [Pg.371]

N-Methoxycarbonyl-2-azabicyclo[3.1.0]hex-3-ene pyrolyzed during 0.5 hr. in the gas phase at 285° N-methoxycarbonyl-l,2-dihydropyridine. Y almost 100%. -This thermal isomerization proceeds faster than with isocyclic analogs. F. W. Fowler, Ang. Ch. 83, 147 (1971) ring expansion by ring opening s. a. T. Tsuji, H. Ishitobi, and H. Tanida, Bull. Chem. Soc. Japan 44, 2447 (1971). [Pg.486]

Potassium hydroxide Ethylenecarboxylic acid esters from cyclic halogenoketals with isocyclic ring opening... [Pg.234]

NitroarenesJ irradiation Photochemical oxidative ring opening of isocyclics... [Pg.52]

Oxidation of hydrocarbon groups—Oxidative ring opening of isocyclics s. 16,308... [Pg.99]

Without additional reagents Migration of carbon-carbon double bonds with preceding photochemical ring opening of isocycles s. iv.a.r. 17, 802... [Pg.229]

Pictet-Spengler type ring closure to l,2,3,4,6,7-hexahydrobenzo[a]quinolizines with preceding oxidative ring opening of isocyclics and subsequent oxidation of aldehydes to carboxylic acids... [Pg.202]

Oxidative ring opening of isocycles Ketocarboxylic acids from a-hydroxyketones... [Pg.312]

Nitric acid (s. a. under NH4-vanadate) Oxidative ring opening of isocycles... [Pg.55]

Silver perchlorate Ring expansion of isocyclics by 1,1-dihalogenocyclopropane ring opening Cyclic 2 -alkoxy-a,) -ethylenehalides... [Pg.370]

Fluorenonel irradiation Isocyclic ring opening by isomerization... [Pg.162]

Selective ring hydrogenation of isocyclics s. 13, 74 Reductive furan ring opening s. U, 74... [Pg.35]

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