5-Hydroxy-2-pentynoic acid

Dihydro-2f/-pyran-2-one has been prepared by reductive cycliza-tion of 5-hydroxy-2-pentynoic acid [2-Pentynoic acid, 5-hydroxy-], which is obtained in two steps from acetylene [Ethyne] and ethylene oxide [Oxirane] 3 and by the reaction of dihydropyran [277-Pyran, 3,4-dihydro-] with singlet oxygen [Oxygen, singlet].4,5 2ff-Pyran-2-one has been prepared by pyrolysis of heavy metal salts of coumalic acid [2//-Pyran-5-carboxylic acid, 2-oxo-],8 by pyrolysis of a-pyrone-6-carboxylic acid [211 - Pyran-6-carboxyl ic acid, 2-oxo-] over copper,7 and by pyrolysis of coumalic acid over copper (66-70% yield).8... 

Pentynoic acid, 5-hydroxy-, 56, 51 2-Pcntynoic acid, methyl ester 55, 76 Peptides, 56, 88 Peracetic acid, 55, 87, 88 Perbenzoic acid, m-chloro-, 55, 88 Perbenzoic acid, 3-chloro-, 56, 1 Peroxydisulfunc acid ([(HO)S-(0)2 ] 2 Ot), diammomum salt, 56, 69 PHASE TRANSFER ALKYLATION, 55,... 

Dihydro-2//-pyran-2-one has been prepared by reductive cycliza-tion of 5-hydroxy-2-pentynoic acid [2-Pentynoic acid, 5-hydroxy-], which is obtained in two steps from acetylene [Ethyne] and ethylene oxide [Oxirane] and by the reaction of dihydropyran [2Jf-Pyran,... 

Hydroxy-2-pentynoic acid, 56, 51 7-Hydroxy-4,4,5,7-tetramethylbicyclo-[4.2.0] octan-2-one, 57, 115 V-Hydroxy-l-(p-tolylsulfonyl)meth-animidoyl chloride, 57, 100 11-HYDROXYUNDECANOIC LACTONE, 58, 98, 100... 

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