Cardenolides of Erysimum suffruticosum

Conclusion Seven cardenolides have been isolated from the seeds ofErysium suffruticosum Spreng.: digitoxigenin, strophanthidin, erysimin, desglucocheirotoxin, desglucoerycordin, canescein, and a new glycoside which we have called bipindogulomethyloside. The latter is bipindogenin 3-O--D-gulomethyloside.Khar'kov Scientific-Research Institute of Pharmaceutical Chemistry. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 178–183, March–April, 1974.     

Stereoselective Synthesis of 3-C-Branched-Chain Sugars by Aldol Reaction of Furanos-3-Uloses with Acetone

Abstract

Aldol reaction of 1,2-O-isopropylidene-5-O-tertbutyl-dimethylsilyl-α-D-erythro-pentofuranos-3-ulose (1) with acetone in the presence of aqueous K₂CO₃ afforded 3-C-acetonyl-1,2-O-isopropylidene-5-O-tertbutyl-dimethylsilyl-α-D-ribofuranose(2). Similar reaction of 1,2:5, 6-di-o-isopropylidene- α-D-ribo-hexofuranos-3-ulose (3) afforded 3-C-acetonyl-1,2:5, 6-di-o-isopropylidene- α-D-allofuranose (4) and (1R, 3R, 7R, 8S, 10R)-perhydro-8-hydroxy-5,5,10-trimethyl-2,4,6,11,14-pentaoxatetracyclo[8,3,1,0^1,8,0^3,7] tetradecane. The stereochemistry of the new chiral centers were determined by ¹H NOE experiments.     

Erysimum glycosides X. Cardenolides of Erysimum cuspidatum

Summary In the separation of the combined polar glycosides from the seeds ofErysimum cuspidatum (M.B.) DC, in addition to cardenolides isolated previously we also obtained cheirotoxin, glucoerysimoside, and a new glycoside which we have called glucolokundjoside. It has been shown that glucolokundjoside has the structure of bipindogenin 3-O-[O--D-glucosyl-(1 4)--L-rhamnopyranoside].The isothiocyanate cheiroline has been isolated from the chloroform fraction.A sample of glucoerysimoside was kindly given to us by I. F. Makarevich (Khar'kov), and a sample of cheirotoxin by T. Reichstein (Basle, Switzerland).Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 166–170, March–April, 1975.     

Cheiranthus allioni — A unique cardenolide-bearing plant

The results of chemical investigations of cardenolides and cardenolide glycosides of plains erysimum (Erysimum asperum, Cheiranthus allioni) have been generalized and analyzed. It has been shown that this plant is distinguished by the presence of an unusually large set of glycosides and aglycons and sugars of diverse chemical structures and by a wealth of isomeric compounds and genetically related substances. On the basis of chemotaxonomic characteristics, plains erysimum has been assigned unambiguously to the genusCheiranthus (wallflower). The promising nature of the practical use of the plant is discussed. The review includes publications that appeared in 1969–1990.All-Union Scientific-Research Institute of Drug Chemistry and Technology, Kharkov. Translated from Khimiya Prirodnykh Soedinenii, Nos. 3,4, pp. 305–312, May–August, 1992.     

Oxygenation of Trimethylsilylallenes Readily Obtainable from Organoboranes. Syntheses of 1-Trimethylsilyl-1-alkyn-3-ones and 1-Trimethylsilyl-1-alkyn-3-ols

Abstract

Recently we have reported that the reaction of sodium methoxide with ate-complexes (1) readily prepared from trimethyl-silylpropargyl phenyl ether and organoboranes gives trimethyl-silylallenes (2) selectively (eq. 1).¹ In an attempt to find a new synthetic application of such silylallenes (2), the oxidation of 2 was examined. Although the usual oxidants such as m-chloro-perbenzoic acid were found to be unsuitable for the oxidation of the silylallenes, it was discovered that 2 was autoxidized at room temperature to propargylic hydroperoxide (3) (eq. 2). For example, the acidified starch-iodine test² strongly suggested the presence of the organic hydroperoxide in the reaction mixture obtained from 1,2-heptadienyltrimethylsilane (2, R=Bu) and oxygen. The hydroperoxide (3, R=Bu) was isolated in a 40% yield by distillation, 45–48 [ddot]C/0.1 mmHg. In the infrared spectrum, the OH stretching frequency appears at 3430 cm^?1 and the C°C at 2180 cm,^?1     

Nonreducing-Sugar Subunit Analogs of Bacterial Lipid a Carrying the Ester-Bound (3R)-3-(Acyloxy)Tetradecanoyl Group

Abstract

In order to elucidate further the relationship between the composition of the fatty acyl groups in the nonreducing-sugar subunit of bacterial lipid A and its biological activity, 3-O-[(3R)-3-(acyloxy)tetradecanoyl]-2-deoxy-2-[(3R)-3-hydroxytetradecanamido]-4-O-phosphono-D-glucose [GLA-63(R, R) and GLA-64(R, R)], and 3-O-[(3R)-3-(acyloxy)tetradecanoyl]-2-deoxy-4-O-phosphono-2-tetradecanamido-D-glucose [GLA-67(R), GLA-68(R) and GLA-69(R)] have been synthesized. Benzyl 2-[(3R)-3-(benzyloxymethoxy)tetradecanamido]-2-deoxy-4,6-O-isopropylidene-β-D-glucopyranoside (5) and benzyl 2-deoxy-4,6-O-isopropylidene-2-tetradecanamido-β-D-glucopyranoside (6) were each esterified with (3R)-3-dodecanoyloxytetradecanoic acid (1), (3R)-3-tetradecanoyloxytetradecanoic acid (2) or (3R)-3-hexadecanoyloxy-tetradecanoic acid (3), to give 7-11, which were then transformed, by the sequence of deisopropylidenation, 6-O-tritylation and 4-O-phosphorylation, into a series of desired compounds.     

Application of Organolithium and Related Reagents in Synthesis,Part 8. Synthesis of 3-Benzylpicolinic and 3-Benzylisonicotinic Acids

The synthesis of 3-benzylpicolinic (5) and 3-benzylisonicotinic (6) acids via ionic reductive cleavage (HI/H₃,PO₂) of the aza-phthalides (3) and (4), is described.     

A Conventient Synthesis of 3-Hydroxy-4-chromanone Using Iodobenzene Diacetate

A useful synthesis of 3-hydroxy-4-chromanone (6) is not currently available. Lead tetraacetate oxidation of 4-chromanone (4) yields the C(3) acetoxy derivative but this compound could not be deacetylated to 6.¹ Recently Donnelly and Maloney reported² that the Algar-Flynn-Oyamada reaction (H₂O₂/CH₃OH/NaOH), which is commonly used for the conversion of o-hydroxychalcones (1) into 3-hydroxyflavanone (2) and 3-hydroxyflavones (3), does not yield 6 when applied to o-hydroxya-crylophenone 1 (R = H). The authors found that under less basic conditions using K₂CO₃ some 6 is formed but the major product is catechol. These observations clearly indicate the necessity of developing a method for making 6. The present note describes a staightforward way of preparing 3-hydroxy-4-chromanone (6) in good yield.     

Synthesis of N-[2-S -(2-Acetamido-2,3-dideoxy-D-glucopyranose-3-y1)-2-Thio-D-Lactoyl]-L-alanyl-D-isoglutamine

Abstract

N-[2-S-(2-Acetamido-2,3-dideoxy-D-glucopyranose-3-y1)-2-thio-D-lactoyl]-L-alanyl-D-isoglutamine, in which the oxygen atom at C-3 of N-acetylmuramoic acid moiety in N-acetylmuramoyl-L-alanyl-D-isoglutamine (MDP) has been replaced by sulfur, was synthesized from allyl 2-acetamido-2-deoxy-β-D-glucopyranoside (1).

Treatment with sodium acetate of the 3-O-mesylate, derived from 1 by 4,6-O-isopropylidenation and subsequent mesylation, gave allyl 2-acetamido-2-deoxy-4,6-O-isopropylidene-β-D-allopyranoside (4). When treated with potassium thioacetate, the 3-O-mesylate, derived from 4, afforded allyl 2-acetamido-3-S-acetyl-2-deoxy-4,6-0-isopropylidence-β-D-glucopyranoside (6). S-Deacetylation of 6, condensation with 2-L-chloropropanoic acid, and subsequent esterification, gave the 3-s[D-1(methoxycarbonyl)ethyl]-3-thio-glucopyranoside derivative (7). Coupling of the acid, derived from 7, with the methyl ester of L-alanyl-D-isoglutamine, and subsequent hydrolysis, yielded the title compound.     

Addition of Some Enamino Esters to 3-Substituted Coumarins

The addition of the enamino esters 1a, b to several coumarins with electron-withdrawing 3-substituents 2 yielded 3 and 4, whereas ethyl 3-amino-2-butenoate (1c) reacted surprisingly with its C-4 to give either an adduct 8 or pyrido [3,4-c] chromene 9.     

A Simple Preparation of 3-Formyl-Cycloalkenones

Recently, we required a convenient method for preparing the 3-formyl-cyclohexenone, 1, starting from dihydroresorcinol. The conversion of dihydroresorcinol into the cyclohexenone derivative 2, could be readily accomplished using the elegant method of Stork and Danheiser,¹ however, existing methods for the transformation of the ketone group of 2 into the formyl group of 1 did not prove satisfactory.² We describe here, a simple and general method for the transformation of 2 into 1 (Scheme I).     

The Reaction of Phosphonium Ylids with o-Quinones and Triketones

Abstract

The reaction of 1,2-benzo [a] phenazine-8, 9-dione 1 and/or 1,2,3-indantrione 2, with phosphonium ylides has been studied. When 1 was reacted with two molar amounts of methoxy-(3a) and/or ethoxycarbonylmethylenetriphenylphosphorane (3b), in THF, at the reflux temp, for 3 hrs, dimethyl (4a) and/or diethyl 1,2-dihydrobenzo a furo [3,2-h] phenazine-1,2-dicarboxylate (4b), along with triphenylphosphine oxide and triphenylphosphine were obtained. On the other hand, reaction of equimolar amounts of ylides 3 with the red trione 2 in THF at room temp., afforded colourless crys tals of 2′,4′-dihydroxyspiro [indan-2,3′ (2′H)-indeno [1,2-b] pyran]-1,3,5′(4′H)-trione diacetate (5a) or dipropionate (5b), together with triphenylphosphine oxide. Formation of 6-membered dihydro aromatic ring like 5, is considered as a new reaction of phos phoranes. The structure of the new compounds 4 and 5 was confirmed and the reaction mechanisms are discussed.     

REACTIONS WITH 3-CHLORO-1,2-BENZISOTHIAZOLIUM CHLORIDES: A NEW SYNTHESIS OF 3-AMINO-BENZO [B] THIOPHENES

Abstract

3-Chloro-1,2-benzisothiazolium chlorides 1 react with activated methylene groups of ketones. Via a ring-opened intermediate 2, 2,3-dihydro-3-imino-benzo [b] thiophenes 3 are obtained, which may be cleaved to the 3-amino-benzo [b] thiophenes 4 and 5.     

New Nitrogen Derivatives of Podophyllotoxin and a Novel Access to Dehydroanhydropicropodophyllin

The new compounds podophyllotoxone oxime (3) and epipodophyllotoxin azide (5) were prepared. The known dehydroanhydropicropodophyllin (6) was unexpectedly obtained from podophyllotoxin (1) by treatment with TMSCl/NaI/MeCN.     

Glycosides of Erysimum

Summary The cardenolides of six species ofErysimum and ofSyrenia siliculosa have been studied. The cardiac glycosides erysimin and erysimoside have been found inE. altaicum, E. marschallianum, E. nuratensae, andS. siliculosa. In addition to these glycosides,E. diffusum has yielded desglucocheirotoxin, canescein, and a new cardenolide, erydiffuside,E. violascens has yielded gypsobioside, andE. cuspidatum has yielded a new glycoside cuspidoside.Khimiya Prirodnykh Soedinenii, Vol. 3, No. 2, pp. 173–178, 1967     

Synthesis and Some Reactions of 4-Aroyl-3-Chloro-6-p-Tolylpyridazines

4-Aroyl-3-chloro-6-p-tolylpyridazines (3a &b) were prepared by the action of phosphorous oxychloride on (2). (3a &b) react with hydrazine hydrate to give the pyrazolinopyridazines (4a &b) and with hydroxylamine hydrochloride to give the isoxazolopyridazines (7a &b), respectively. (4b) was also synthesized by the action of phosphorous oxychloride on the hydrazone (5). The reaction of (3a &b) with primary amines in boiling ethanol gives (8a-e), while their reaction with primary aromatic amines in the presence of solvent gives the Schiff's bases (9a-c).     

A New Synthesis of 3-Deoxy-D-arabino-hexose and its Tautomeric Equilibrium

Abstract

The title compound was synthesized in four steps from D-glucono-1,5-lactone. Reduction of 2,4,6-tri-O-benzoyl-3-deoxy-D-arabino-hexono-1,5-lactone (1) with disiamylborane afforded 2,5,6-tri-O-benzoyl-3-deoxy-D-arabino-hexopyranoae (2) which, on debenzoylation, gave 3-deoxy-D-arabino-hexoae (3). Tautomeric equilibrium of 3 was studied by ¹H and ¹³C NMR spectroscopy.     

A Simple Synthesis of 2-Deoxy-3-O-Methyl-D-Arabino-Hexose VIA Photodeoxygenation

2-Deoxy-3-O-methyl-D-arabino-hexose (2) was synthesized by photodeoxygenationin hexamethyl-phosphor-triamide/water with light of 254 nm. The isopropylidene-protecting group was photochemically resistent, whilst the benzylidene group was cleaved.     

Synthesis of 2, 3-dideoxy-4-O-p-methoxybenzyl-L-erythro-hex-2-enono-1, 5-lactone

The synthesis of 2, 3-dideoxy-4-O-p-methoxy-benzyl-L-erythro-hex-2-enono-1, 5-lactone 9 from L-serine, using (1RS, 3S)-3, 4-isopropylidene-1-methoxy-1-phenylthio-butan-2-one 2 as key chiral intermediate, is described. Compound 9 is an interesting chiral precursor for the synthesis of L-sugars.