Simple and effective synthesis of isoflavones and 3-aryloxychromones

Conditions have been developed for an effective synthesis of 7-hydroxy- and 5,7-dihydroxyisoflavones and also of 3-aryloxy-7-hydroxychromones. The disadvantages and advantages of alternative pathways for the synthesis of these compounds are discussed. The proposed method of synthesis permits considerable simplification of the preparation of compounds of these series. T. G. Shevchenko Kiev State University. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 639–643, September–October, 1989.     

A Wacker-Cook synthesis of isoflavones: formononetine

A total synthesis of the isoflavone formononetine 1 by an oxidative Pd-mediated cyclization of α-methylenedeoxybenzoins 4a-c is described. Substrates 4a-c were rapidly assembled using ‘protected cyanohydrin’ chemistry.     

Synthesis of fluorine-containing 3-hydroxyflavanones and isoflavones

Fluorine-containing 3-hydroxyflavanones and isoflavones were synthesized by epoxidation of F-containing chalcones by hydrogen peroxide under basic conditions and subsequent intramolecular cyclization of the resulting epoxides using BF₃·Et₂O. The ratio of products depended on the presence and position of the F atom.     

Simple and effective 3D recognition of domoic acid using a molecularly imprinted polymer

We have developed a simple and effective molecular imprinting technique to target compounds with flexible structure. Domoic acid (DA), an amnesic shellfish poison, was used as the target compound while many acidic compounds (mono-, di-, and tricarboxylic acids) were used as template molecules for molecularly imprinted polymers (MIPs). Evaluation of selective recognition abilities using liquid chromatography revealed that the highest selective recognition ability for DA was found when pentane-1,3,5-tricarboxylic acid (1,3,5-PeTA) was used as the template. Computer modeling studies of the DA structure suggested that the observed selective recognition depended on the structural changes in DA at the recognition site of the MIPs as well as spatial distance between the COOH groups in DA and 1,3,5-PeTA. Using the 1,3,5-PeTA-MIP, we could easily purify DA from blue mussel extracts by solid-phase extraction.     

Simple synthesis of 3-(N-alkylamino)-1-propanols

Various 3-(N-alkylamino)-1-propanols were obtained by the lithium aluminum hydride reduction of the products of the reaction of 3-amino-1-propanol with carbonyl compounds. This method for the synthesis of aminopropanols is applicable in the case of optimal electrophilicity of the carbonyl component.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2154–2157, September, 1991.     

Total synthesis of apios isoflavones and investigation of their tyrosinase inhibitory activity

Apios isoflavone glucosides 1 and 2 were synthesized for the first time via Friedel–Crafts reaction, Bischler–Napieralski-type cyclization, and phase-transfer catalyzed glycosylation as the key steps. In addition, aglycones 4 and 5 and related natural isoflavone cajanin (6) were synthesized in short steps. Evaluation of the inhibitory activity of these compounds toward tyrosinase indicated that all the compounds were active. In particular, the half-maximal inhibitory concentration of compound 1 toward tyrosinase was measured to be 729 μM.     

Simple and effective preparation of amino sulfonylureas from amino acids: application to the synthesis of amino sulfonylurea-containing peptidomimetics

Several amino sulfonylureas have been synthesized, starting from amino acids. The synthetic procedure is simple affording high yields of products under mild conditions. Furthermore, it is shown that these compounds can be incorporated into a peptide sequence.     

A simple and effective synthesis of activated vinylphosphonates from 3-methoxy-2-diethoxyphosphorylacrylate

A facile, efficient and general one-step procedure for the synthesis of 3-substituted 2-diethoxyphosphorylacrylates from 3-methoxy-2-diethoxyphosphorylacrylate 1b and nitrogen, carbon and phosphorus nucleophiles is presented. Reaction of 1b with 3,5-dimethoxyphenol in the presence of trifluoromethanesulfonic acid yields 3-diethoxyphosphoryl-5,7-dimethoxychromen-2-one.     

Simple total synthesis of sarkomycin

A simple total synthesis of sarkomycin starting from methyl 2-oxo-5- vinylcyclopentane-1-carboxylate is described.     

Simple synthesis of substituted pyrroles

Simple synthesis of substituted pyrroles using iodine-catalyzed and montmorillonite KSF-clay-induced modified Paal-Knorr methods has been accomplished with excellent yields. N-Substituted carbazole has also been prepared by following this method. If one of the reactants is a liquid, the reaction proceeds exceedingly well without a solvent. This method gives pyrroles with less nucleophilic multicyclic aromatic amines at room temperature.     

Simple synthesis of conjugated bromoallenes

Conclusions A convenient method has been developed for the synthesis of conjugated bromoallenes starting from-acetylenic alcohols.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1442–1444, June, 1972.     

Practical and efficient entry to isoflavones by Pd(0)/C-mediated Suzuki-Miyaura reaction. Total synthesis of geranylated isoflavones

A scalable synthesis of isoflavones taking advantage of the Suzuki-Miyaura reaction catalyzed by Pd(0)/C is described. The approach developed has been extended to the total synthesis of 7-O-geranylformononetin, griffonianone D, and conrauinone D, which did not display cytotoxicity against human HeLa carcinoma cells. In addition, this study established unambiguously the absolute configuration of natural griffonianone D.     

Simple and convenient one-pot synthesis of cyclooctatetraene

Cyclooctatetraene is readily synthesized by the oxidation of in situ generated [Li(TMEDA)]₂[C₈H₈] with 1,2-dibromoethane. The product is readily isolated and produced without the use of hazardous or toxic reagents.     

Simple and effective one‐pot synthesis of (meth)acrylic block copolymers through atom transfer radical polymerization

The synthesis of di‐ and triblock copolymers using atom transfer radical polymerization (ATRP) of n‐butyl acrylate (BA) and methyl methacrylate (MMA) is reported. In particular, synthetic procedures that allow for an easy and convenient synthesis of such block copolymers were developed by using CuBr and CuCl salts complexed with linear amines. Polymerizations were successfully conducted where the monomers were added to the reactor in a sequential manner. Poor cross‐propagation between poly(n‐butyl acrylate) (PBA) macroinitiators and MMA was minimized, and therefore control of molecular weights and distributions was realized, by using halogen exchange—a technique involving the addition of CuCl to the MMA during the chain extension of the PBA macroinitiator. High molecular weight (M_n ∼ 90,000) and low polydispersity (M_w /M_n < 1.35) ABA triblock copolymers were also prepared and their structure and properties in bulk have been preliminary characterized indicating the potential of ATRP for the production of all‐acrylic thermoplastic elastomers. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2023–2031, 2000