Asymmetric Diels-Alder Reaction of 5,5,5-Trichloro-3-penten-2-one and Its Related Compound

Diels-Alder reactions of 5,5,5-trichloro-3-penten-2-one and ethyl 4,4,4-trichloro-2-butenoate with cyclopentadiene in the presence of a chiral Lewis acid gave exo-2-acetyl-endo-3-trichloromethyl-bicyclo[2.2.1]hept-5-ene and exo-2-ethoxycarbonyl-endo-3-trichloromethylbicyclo[2.2.1]hept-5-ene with 40% and 7% e.e., respectively

A Novel Synthesis of Symmetric Trienes

This paper describes a novel synthesis of trienes by treatment of trans-2-alkenyl triphenylphosphonium bromides with BuLi in THF solution. Compounds, 5,7,9-tetradecatriene, 1,6-diphenyl-1,3,5-hexatriene, and 2,6,11,16-tetramethyl-2,6,8,10,14-hexadecapentaene were prepared in the yields of 40%, 9%, and 46%, respectively. Cross-coupling of trans-2-heptenyltriphenylphosphonium bromide and trans-3-phenyl-2-propenyltriphenylphosphonium bromide gave a mixture of 5,7,9-tetradecatriene (10.6%), 1,6-diphenyl-1,3,5-hexatriene (0.5%), and 1-phenyl-1,3,5-decatriene (9.4%)

1,3-Dibromo-5,5-dimethylhydantoin, a useful reagent for ortho-monobromination of phenols and polyphenols

Ortho-monobromination of phenols and polyphenols by 1,3-dibromo-5,5-dimethylhydantoin (DBDMH) is described. A simple addition of commercially available DBDMH to phenols and polyphenols in chloroform at room temperature resulted in a good to excellent yield of corresponding ortho-monobromo derivatives

Synthesis of ellagic acid and its 4,4'-di-Ο-alky derivatives from gallic acid

Synthesis of ellagic acid and its 4,4'-di-Ο-alkyl derivatives from gallic acid is described. Ellagic acid is prepared by oxidative coupling of gallic acid with ο-chloranil. Functionalized methyl bormogallate underwent Ullmann coupling to give the biphenyl that upon lactonization resulted in the ellagic acid and its alkoxy derivatives

Asymmetric Synthesis of Optically Active Malic Acid

Chiral reduction of 2-oxosuccinic acid esters with fermenting bakers' yeast gave (S)-(-)- malic acid esters in 34-54% isolated yield with 85-100% ee

Condensation of 4-hydroxy-2-thiazolines with 1,2-phenylenediamine as a novel effective route to thiazolo[3,4-a]quinoxalines

Thiazolo[3,4-a]quinoxalin-4-ones were prepared in two steps starting from methyl phenylchloropyruvate using a new strategy for the construction of the ring system. A key step in this new method involves the reaction of 4-hydroxytetrahydrothiazoles with 1,2-phenylendiamines

A Novel Synthesis ofSymmetric Trienes

This paper describes a novel synthesis of trienes by treatment of trans-2-alkenyl triphenylphosphonium bromides with BuLi in THF solution. Compounds, 5,7,9-tetradecatriene, 1,6-diphenyl-l,3,5-hexatriene,and 2,6,11, 16-tetramethyl-2,6,8,10,14-hexadecapentaene were prepared in the yields of 40%, 9%, and 46%, respectively. Cross-coupling of trans-2-heptenyltriphenylphosphonium bromide and trans-3-phenyl-2-propenyltriphenylphosphonium bromide gave a mixture of 5,7,9-tetradecatriene <I0.6%), 1,6-diphenyl-l,3,5-hexatriene (0.5%), an