55555-33-4Relevant academic research and scientific papers
Copper-Catalyzed Oxidative Cyclization of Carboxylic Acids
Sathyamoorthi, Shyam,Du Bois
, p. 6308 - 6311 (2016/12/23)
A method for converting C-H to C-O bonds through oxidative cyclization of carboxylic acids to generate lactone products is described. The reaction employs catalytic amounts of Cu(OAc)2 and potassium persulfate as the terminal oxidant and is performed open to air in an aqueous acetic acid solvent system. Preliminary mechanistic studies suggest that substrate oxidation likely proceeds by sulfate radical anion and that the Cu catalyst has no influence on the product-determining step. These conclusions differ from related investigations that propose the intermediacy of a carboxylate radical.
Synthesis of 3-substituted 8-hydroxy-3,4-dihydroisocoumarins via successive lateral and ortho-lithiations of 4,4-dimethyl-2-(o-tolyl)oxazoline
Tahara, Naruki,Fukuda, Tsutomu,Iwao, Masatomo
, p. 5117 - 5120 (2007/10/03)
Sequential treatment of 4,4-dimethyl-2-(o-tolyl)oxazoline in THF with sec-BuLi, aromatic or aliphatic aldehydes, sec-BuLi, B(OMe)3, and H2O2 produced the laterally alkylated and ortho-hydroxylated oxazolines in one-pot. Treatment of these products with TFA in aqueous THF provided 3-substituted 8-hydroxy-3,4-dihydroisocoumarins in 44-75% overall yields. This procedure allowed the short synthesis of (±)-hydrangenol and (±)-phyllodulcin, naturally occurring 3,4-dihydroisocoumarins of pharmacological interest. A more economical synthesis of (±)-phyllodulcin via the trianion intermediate is also described.
Efficient syntheses of (+/-)-hydrangenol, (+/-)-phyllodulcin and (+/-)-macrophyllol
Guenes, Mehmet,Speicher, Andreas
, p. 8799 - 8802 (2007/10/03)
In this paper we report on a efficient and flexible synthetic route towards the total syntheses of the dihydrocoumarine derivatives hydrangenol (1), phyllodulcin (1a) and macrophyllol (6b). The syntheses started with a readily available phosphonium salt 2 and suitable modified benzaldehydes 3/3a/3b resulting in 46 to 61 percent overall yields in three to four-steps sequences. The racemic products could be separated by chiral HPLC. The evidence of the (R)-enantiomer for sweetness could be demonstrated for 1a.
SYNTHESES OF DIHYDROISOCOUMARINS, (+/-)-HYDRANGENOL AND (+/-)-PHYLLODULCIN, UTILIZING AN ANNELATION REACTION OF ENAMINONES WITH ETHYL ACETOACETATE. STUDIES ON THE β-CARBONYL COMPOUNDS CONNECTED WITH THE β-POLYKETIDES XIII
Takeuchi, Naoki,Nakano, Takako,Goto, Kaori,Tobinaga, Seisho
, p. 289 - 297 (2007/10/02)
Naturally occurring dihydroisocoumarins, (+/-)-hydrangenol (1) and (+/-)-phyllodulcin (2) were synthesized from the enaminones (3) and (4) by the annelation reactions with ethyl acetoacetate (5).
SYNTHETIC APPROACH TO OPTICALLY ACTIVE 3-ARYL-3,4-DIHYDROISOCOUMARINS
Arnoldi, Anna,Bassoli, Angela,Merlini, Lucio,Ragg, Enzio
, p. 403 - 407 (2007/10/02)
Some optically active 3-aryl-3,4-dihydroisocoumarins have been obtained by enantioselective reduction of the corresponding aryl 2-carboxybenzyl ketones with the CBS catalyst.The ketones were obtained by the condensation of the o-toluate carbanion with ald
Ortho-Lithiated Tertiary Benzamides. Chain Extension via o-Toluamide Anion and General Synthesis of Isocoumarins Including Hydrangenol and Phyllodulcin
Watanabe, Mitsuaki,Sahara, Masanori,Kubo, Masaki,Furukawa, Sunao,Billedeau, R. J.,Snieckus, V.
, p. 742 - 747 (2007/10/02)
Lithiation of N,N-diethyl-2-methylbenzamide (2a) followed by condensation with aromatic aldehydes and basic hydrolysis leads to 3-aryl-3,4-dihydroisocoumarins 4 in modest overall yields.Adoption of this methodology to N,N-dimethyl-2-methyl-6-methoxybenzamide (7b) provides isocoumarins 9a and 9b which by selective demethylation procedures yields hydrangenol (10a) and phyllodulcin (10c), naturally occurring isocoumarins of pharmacological interest.A one-pot, abbreviated procedure for the preparation of both 9a and 9b starting with N,N-Dimethyl-2-methoxybenzamide (6c) is also described.
An Easy Two-Synthon Synthesis of a Sweet Dihydroisocoumarin, (+/-)-Phyllodulcin. Studies on the β-carbonyl Compounds Connected with β-Polyketides. IX
Takeuchi, Naoki,Ochi, Kazue,Murase, Masayuki,Tobinaga, Seisho
, p. 4360 - 4363 (2007/10/02)
(+/-)-Phyllodulcin (1), a sweet dihydroisocoumarin of Hydrangea serrata SERINGE var. thunbergii SUGIMOTO, was synthesized by aromatic annelation of two synthons 2 and 3 to yield 5, followed by successive debenzylation, hydrolysis, lactonization, and decar
DIRECTED METALATION OF TERTIARY BENZAMIDES. SHORT SYNTHESES OF HYDRANGENOL AND PHYLLODULCIN
Watanabe, M.,Sahara, M.,Furukawa, S.,Billedeau, R.,Snieckus, V.
, p. 1647 - 1650 (2007/10/02)
Brief syntheses of isocumarin natural products hydragenol(2) and phyllodulcin(3) via ortho-lithiated benzamide intermediates are described.
Biogenetic-type Synthesis of (+/-)-Phyllodulcin, a Sweet Principle of Hydrangea serrata Seringe var. thunbergii Sugimoto (Studies on the β-Carbonyl Compounds connected with the β-Polyketides. VI)
Takeuchi, Naoki,Murase, Masayuki,Ochi, Kazue,Tobinaga, Seisho
, p. 3013 - 3019 (2007/10/02)
A biogenetic-type synthesis of (+/-)-phyllodulcin (2), a sweet principle of Hydrangea serrata SERINGE var. thunbergii SUGIMOTO, from 3-(3-benzyloxy-4-methoxyphenyl)-2-propenal (7) modelled on the polyketide mode of biosynthesis is described.Keywords - β-p
An Easy Two Synthon Synthesis of a Sweet Dihydroisocoumarin, (+/-)-Phyllodulcin
Takeuchi, Naoki,Ochi, Kazue,Murase, Masayuki,Tobinaga, Seisho
, p. 593 - 594 (2007/10/02)
A short synthesis of (+/-)-phyllodulcin (1), a sweet principle of Hydrangea serrata Seringe var. thunbergii Sugimoto, from the enaminone (2) by annelation with dimethyl 3-oxaglutarate is decribed.
