Muconic acid anhydride

Oxygenation catalyst. This vanadium catalyst is a particularly active catalyst lor oxygenation of 3,5-di-t-butylpyrocatechol (1) to the muconic acid anhydride 2, the 7-pyronc 3, and the o-quinone 4, which cannot be oxidized to 2 under these conditions.1... 

Muconic acid anhydride 4,6-di-t-Butyl-2H-pyra-n-2-one spiro [1,4-benzodioxin-2(3H), 2 -[2H]pyran]-3-one 4, 6,6, 8-tetrakis (1,1 -dimethylethyl) 3,5-di-t-butyl-5 (carboxymethyl) -2-furanone 3, 5-di-t-butyl-l, 2-benzoquinone... 

The photochemical isomerization of the muconic acid anhydride (304) to the bicyclic compound (305) has been reported to occur in high yield. 

The catalytic reaction of complex 49 with dtbcH2 and dioxygen is less selective than that of 50. In addition to the formation of dtbq and 3,5-di-ter -butyl-l-oxa-cyclohepta-3,5-diene-2,7-dione, some muconic acid anhydride and 2-pyrone derivatives are also produced as a result of both intra- and extradiol insertion of one of the oxygen atoms from dioxygen. Such products are consistent with the mechanism in Scheme 10, with the proviso that both the rhodium and iridium systems share the same mechanism, at least in the initial stages of the reaction. 

Oxepan and other oxygen- or nitrogen-containing saturated heterocycles can be prepared in high yield by the dehydrative coupling of aamino-alcohols, using diethyl azodicarboxylate and triphenylphosphine. The synthetically useful oxepin-2,7-diones (muconic acid anhydrides) can be conveniently prepared by the oxidation of ortho-henzoquinones with w-chloroperoxybenzoic acid. °... 

Intradiol oxygenation produces mainly the carboxymethylfuranone derivative 15 via the corresponding muconic acid anhydride DBMUA. The extradiol path affords mainly formylfuranone 5 via the cyclic... 

Ruthenium-catalyzed oxygenation of catechols gives muconic acid anhydride and 2H-pyran-2-one [123]. 

Formula 366) gives a bicyclic enol ether (Formula 367) which is hydrolyzed to Formula 368 (161,162). The sequence of Formulas 366-368 represents a potentially general synthesis of bicyclic cyclobutanone derivatives. A clever synthesis of m-3-cyclobutene-l,2-dicarboxylic acid anhydride (Formula 369) has been accomplished by irradiation of muconic anhydride (Formula 370) in ether (163). 

Reagent 1 also converts anhydrides such as 2, prepared as indicated, to muconic acid derivatives (3 and 4) (equation II).3... 

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