The First Synthesis of (4S,5R,6R)‐5,6‐Dihydroxy‐4‐(prop‐1‐en‐2‐yl)cyclohex‐1‐ene‐1‐carboxylic Acid

A putative acid metabolite of a novel highly effective antiparkinsonian agent, (4S,5R,6R)‐5,6‐dihydroxy‐4‐(prop‐1‐en‐2‐yl)cyclohex‐1‐ene‐1‐carboxylic acid ( 5 ), was synthesized for the first time. Several synthetic approaches based on different transformations of O‐bearing monoterpenoids of the pinane and p‐menthane series were developed and tested in the course of the study. Acid 5 was synthesized starting from a commercially available monoterpenoid, (?)‐verbenone, in a total yield of 4.4% over eight steps.     

Syntheses of substituted 2‐(2‐alkylthio‐1‐benzyl‐5‐imidazolyl)‐1,3,4‐oxadiazoles

Starting from the readily available benzylamine hydrochloride a series of 2‐(2‐alkylthio‐1‐benzyl‐5imida‐zolyl)‐1,3,4‐oxadiazoles were prepared.     

Syntheses of 2‐alkylthio‐1‐[4‐(N‐α‐ethoxycarbonylbenzyl)‐aminobenzyl]‐5‐hydroxymethylimidazoles

Starting from the readily available p‐nitrobenzylamine a series of 2‐Alkylthio‐1‐[4‐(N‐α‐ethoxycarbonylbenzyl)aminobenzyl]‐5‐hydroxymethylirnidazoles were prepared.     

Facile access to 6‐substituted 1,4,5,7‐tetrahydropyrrolo[3,4‐b]‐pyridines via hantzsch type dimethyl 4‐aryl‐2‐formyl‐6‐methyl‐1,4‐dihydropyridine‐3,5‐dicarboxylates

Efficient assembly of 6‐substituted 4‐aryl‐5‐oxo‐1,4,5,7‐tetrahydropyrrolo[3,4‐b]pyridines (7a‐f) is described according to a Hantzsch type reaction from formyl‐ester 4 by imination, borohydride reduction and intramolecular thermal amino‐ester cyclization. The starting compound 4 was prepared in three steps from the readily available formyl derivative 1, methyl 4,4‐dimethoxy‐3‐oxobutanoate and methyl 3‐aminocrotonate.     

Synthesis of 1,3‐bis(2‐trimethylsilyloxyhexafluoro‐2‐propyl)‐5‐allylbenzene and its introduction into polysiloxane chains

The synthesis of 1,3‐bis(2‐trimethylsilyloxyhexafluoro‐2‐propyl)‐5‐allylbenzene ( IV ) is described, starting from commercially available 1,3‐bis(2‐hydroxyhexafluoro‐2‐propyl)benzene. After the first step of iodination was optimized, a series of metallating agents were tested, before allylation, so that the best reagent could be selected. The allyl compound IV was then added to two different copoly(dimethyl‐methylhydro)siloxanes, PS 122.5 and PS 123 from Gelest/ABCR, via platinum‐catalyzed hydrosilylation, for the preparation of new polysiloxanes bearing specifically designed pendant aryl moieties. The different synthesized products were characterized by spectroscopic methods (IR and ¹H, ¹³C, ¹⁹F, and ²⁹Si NMR), and the glass‐transition temperatures of copolymers VI‐2 , VI‐3 , and VI‐4 were measured. It was shown that the higher the amount was of grafted fluoroaryl groups, the higher the glass‐transition temperature was. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1400–1410, 2003     

Four Syntheses of 4‐Amino‐3,5‐dinitropyrazole

In this paper, syntheses of 4‐amino‐3,5‐dinitropyrazole from four different starting materials are described. The starting materials were 4‐nitropyrazole, 4‐nitro‐3,5‐dimethylpyrazole, 3,5‐dinitropyrazole, and 4‐chloropyrazole, respectively. They are compared in terms of yield, number of steps and suitability for scale‐up into pilot scale production. The overall yield, calculated from commercially available starting materials, ranged from 21% in the case of synthesis via 3,5‐dinitropyrazole up to 61% for the one starting from 4‐chloropyrazole. With numerous factors taken into account, the latter was chosen for a pilot scale study and the product could be produced in batches of 200 g.     

Novel Bis(2‐(5‐((5‐phenyl‐1H‐tetrazol‐1‐yl)methyl)‐4H‐1,2,4‐triazol‐3‐yl)phenoxy)Alkanes: Synthesis and Characterization

In this study, 10 different substituted aromatic bis‐benzaldehydes were synthesized by treating hydroxy benzaldehydes with various dihaloalkanes. Bis aldehydes 5a , 5b , 5c , 5d , 5e , 5f , 5g , 5h , 5i , 5j were treated with 2‐(5‐phenyl‐1H‐tetrazole‐1‐yl)acetohydrazide ( 3 ) in acidic medium and in the presence of ammonium acetate to yield a series of new isomeric bis(2‐(5‐((5‐phenyl‐1H‐tetrazol‐1‐yl)methyl)‐4H‐1,2,4‐triazol‐3‐yl)phenoxy)alkanes ( 6a , 6b , 6c , 6d , 6e , 6f , 6g , 6h , 6i , 6j ) in excellent to good yield. The newly synthesized compounds were characterized by the available spectroscopic analysis.     

Zoledronate complexes. I. Poly[[μ2‐aqua[μ3‐1‐hydroxy‐2‐(1H,3H‐imidazol‐3‐ium‐1‐yl)ethylidenediphosphonato]potassium(I)] monohydrate]

The title compound, {[K(C₅H₉N₂O₇P₂)(H₂O)]·H₂O}_n, is polymeric and consists of layers parallel to (001) interconnected by hydrogen‐bonding and π–π interactions. The K⁺ cation is eightfold coordinated in a KO₈ environment by O atoms from three different chelating zoledronate units and two coordinated water molecules. The zoledronate group presents its usual zwitterionic character, with negative charges in the singly protonated phosphonate groups and a positive charge at the protonated imidazole N atom. The anion binds to three different K⁺ cations in a (so far unreported) triply chelating manner. Intra‐ and interplanar interactions are enhanced by a variety of hydrogen bonds involving all available O—H and N—H donors. A strong imidazole–phosphonate C—H...O interaction is present in the structure.     

Facile synthesis of 5‐aryl‐1‐[(arylamino)methyl]‐ 1,3,5‐triazinane‐2‐thiones

A series of 5‐aryl‐1‐arylaminomethyl‐1,3,5‐triazinane‐2‐thiones has been prepared in a one‐step procedure from condensation of readily available aromatic amines with thiourea and formaldehyde. A mechanism is presented to account for the formation of the products. The overall sequence provides a simple and efficient route to prepare in good to excellent yields and in a short experimental time. J. Heterocyclic Chem., (2012).     

Synthesis of 2‐(3‐indolyl)‐1,4‐naphthoquinones using 3‐iodoindoles

The usefulness of 3‐iodoindoles available for introduction of an indole unit is presented. The reaction of various halo‐3‐iodoindoles with 1,4‐naphthoquinone gave the corresponding 2‐(3‐indolyl)‐1‐4,naphthoquinones in moderate yields. The 3‐iodoindole was used for synthesis of a compound containing both naph‐thazarin and indole skeletons.     

Syntheses of 5‐alkylthio‐1,3‐diaryl‐1,2,4‐triazoles

Arylation of the readily available 3‐alkythio‐5‐aryl‐1,2,4‐triazoles gave 5‐alkylthio‐1,3‐diaryl‐1,2,4‐triazoles in moderate yield. The structures of the latter were confirmed by NOE and ¹³C‐NMR.     

C−H Acetoxylation‐Based Chemical Synthesis of 17 β‐Hydroxymethyl‐17 α‐methyl‐18‐norandrost‐13‐ene Steroids

Palladium‐catalyzed C?H acetoxylation has been proposed as a key transformation in the first chemical synthesis of steroids bearing a unique 17β‐hydroxymethyl‐17α‐methyl‐18‐nor‐13‐ene D ‐fragment. This C?H functionalization step was crucial for inverting the configuration at the quaternary stereocenter of a readily available synthetic intermediate. The developed approach was applied to prepare the metandienone metabolite needed as a reference substance in anti‐doping analysis to control the abuse of this androgenic anabolic steroid.     

Palladium‐Catalyzed Oxidative Cycloisomerization of 2‐Cinnamyl‐1,3‐Dicarbonyls: Synthesis of Functionalized 2‐Benzyl Furans

A new palladium‐catalyzed intramolecular oxidative cycloisomerization of readily available starting materials, 2‐cinnamyl‐1,3‐dicarbonyls, has been demonstrated for the creation of structurally diverse 2‐benzyl furans. The cycloisomerization occurs by a regioselective 5‐exo‐trig pathway. The reaction shows a broad substrate scope with good to excellent yields. Furthermore, a one‐pot procedure has been executed by using readily available cinnamyl alcohols and 1,3‐diketones.     

Synthesis of Epigoitrin from (R)‐(+)‐4‐Hydroxy‐γ‐butyrolactone

Epigoitrin is one of the major components of several natural species, including Isatis indigotica Fort, turnip, and cabbage. It presents antithyroid and antivirus activities. Here, we report an efficient and practical method for the chemical synthesis of epigoitrin from commercially available (R)‐(+)‐4‐hydroxy‐γ‐butyrolactone.     

4,10‐Dibromoanthanthrone as a New Building Block for p‐Type,n‐Type,and Ambipolar π‐Conjugated Materials

New p‐type, n‐type, and ambipolar molecules were synthesized from commercially available 4,10‐dibromoanthanthrone dye. Substitution at the 4,10‐ and 6,12‐positions with different electron‐rich and electron‐poor units allowed the modulation of the optoelectronic properties of the molecules. A bis(dicyanovinylene)‐functionalized compound was also prepared with a reduction potential as low as ?50 mV versus Ag⁺ with a crystalline two‐dimensional lamellar packing arrangement. These characteristics are important prerequisites for air‐stable n‐type organic field‐effect transistor applications.     

Organocatalytic Asymmetric Conjugate Addition of 3‐Monosubstituted Oxindoles to (E)‐1,4‐Diaryl‐2‐buten‐1,4‐diones: A Strategy for the Indirect Enantioselective Furanylation and Pyrrolylation of 3‐Alkyloxindoles

An asymmetric conjugate addition of 3‐monosubstituted oxindoles to a range of (E)‐1,4‐diaryl‐2‐buten‐1,4‐diones, catalyzed by commercially available cinchonine, is described. This organocatalytic asymmetric reaction affords a broad range of 3,3′‐disubstituted oxindoles that contain a 1,4‐dicarbonyl moiety and vicinal quaternary and tertiary stereogenic centers in high‐to‐excellent yields (up to 98 %), with excellent diastereomeric and moderate‐to‐high enantiomeric ratios (up to 99:1 and 95:5, respectively). Subsequently, cyclization of the 1,4‐dicarbonyl moiety in the resultant Michael adducts under different Paal–Knorr conditions results in two new kinds of 3,3′‐disubstituted oxindoles—3‐furanyl‐ and 3‐pyrrolyl‐3‐alkyl‐oxindoles—in high yields and good enantioselectivities. Notably, the studies presented here sufficiently confirm that this two‐step strategy of sequential conjugate addition/Paal–Knorr cyclization is not only an attractive method for the indirect enantioselective heteroarylation of 3‐alkyloxindoles, but also opens up new avenues toward asymmetric synthesis of structurally diverse 3,3′‐disubstituted oxindole derivatives.     

TBAF‐Mediated Dimerization Reaction of β,γ‐Unsaturated Arylketones

A simple and high‐yield method for the synthesis of several 1,5‐diaryl‐1,5‐dicarbonyl compounds has been established starting from TBAF‐mediated isomerization and dimerization reaction of β,γ‐unsaturated arylketones (allyl arylketones) with mono‐, di‐, and tri‐methoxy groups, which is derived from allylation of commercially available different benzaldehydes and followed by oxidation of the resulting secondary alcohols.     

One‐Pot Synthesis of 3‐Cyano‐2‐pyridones

A versatile synthesis of 3‐cyano‐2‐pyridones via a one‐pot, four‐component condensation of ethyl cyanoacetate, ketones, aldehydes, and ammonium acetate under very mild conditions has been developed. This method provides rapid access to this type of valuable heterocyclic compounds from readily available materials in a single operation.     

Efficient Synthesis of (±)‐Horsfiline through the MgI2‐Catalyzed Ring‐Expansion Reaction of a Spiro[cyclopropane‐1,3′‐indol]‐2′‐one

We report a short synthetic route to (±)‐horsfiline that provides the racemate in five steps from commercially available, substituted isatin in 41% overall yield. Efficient entry into the spiro[oxindole‐pyrrolidine] ring system is possible through the application of the cyclopropane opening/ring expansion chemistry we have described with MgI₂ as a bifunctional catalyst.