98-48-6Relevant articles and documents
Biosynthesis of phloroglucinol
Achkar, Jihane,Xian, Mo,Zhao, Huimin,Frost
, p. 5332 - 5333 (2007/10/03)
Substantial concentrations of phloroglucinol were synthesized by Pseudomonas fluorescens Pf-5 expressing the plasmid-localized phlACBDE gene cluster responsible for biosynthesis of 2,4-diacetylphloroglucinol. Expression in Escherichia coli of a single gene in this cluster, P. fluorescens Pf-5 phlD, led to extracellular accumulation of phloroglucinol. Purification of PhlD to homogeneity afforded an enzyme that catalyzed the conversion of malonyl-CoA into phloroglucinol with Km = 5.6 μM and kcat = 10 min-1. Acetylase and deacetylase activities were observed with the catalyzed interconversions of phloroglucinol, 2-acetylphloroglucinol, and 2,4-diacetylphloroglucinol when phlACB was expressed in E. coli. Beyond the mechanistic implications attendant with the identification of an enzyme that catalyzes the conversion of malonyl-CoA into phloroglucinol, PhlD provides the basis for environmentally benign syntheses of phloroglucinol and resorcinol from glucose. Copyright
Reactions of SO2X mono-substituted arenes with SO3 in nitromethane: electronic and steric directing effects of the sulfonic acid group and some model substituents
Ansink, Harold R. W.,Graaf, Erik J. de,Zelvelder, Erwin,Cerfontain, Hans
, p. 210 - 215 (2007/10/02)
The sulfonation of benzene-SO2X (X = CH3, OCH3, OH, and Cl) and of 1- and 2-naphthalene-SO2X ( X = CH3, OCH3, and Cl) with sulfur trioxide in nitromethane as solvents has been studied.In the benzene series, substitution only occurs at the 3-position irrespective of X; the reaction rates, which are all within the same order of magnitude, are low.Upon sulfonation of the 1-SO2X-substituted naphthalenes, the main sulfonation product (58-80percent) is the 5-sulfonic acid (5-S); in addition, 6-S and small amounts of 3-S and 7-S are formed.Also, the formation of the intermolecular sulfonic anhydride of 1-(methylsulfonyl)naphthalene-5-S is observed.The 2-SO2X-substituted naphthalenes all yield the 5-S and 8-S in a ratio of ca. 4.9.For both the benzene and naphthalene series, insertion of SO3 between the SO2 and X moieties of the chlorosulfonyl and methoxysulfonyl substituents proper takes place.In the benzene series these reactions are fast as compared with the actual ring sulfonation, whereas in the naphthalene series they are, in general, relatively slow.In the naphthalene series the mesomeric directing effect of the SO2X groups is less important than in the benzene series; the "naphthalene α-effect" also plays an important role.
