Reactions of Cyclic Anhydrides XIV. Facile Syntheses of Fused Heterocycles via Anilic Acids Pyridobenzoxazinones,Isoquinolinobenzoxazinones and Isocoumarinoquinolines

o-Carboxyhomomaleanilic acids (5) and o-carboxyhomophthalanilic acids (6) on treatment with sodium acetate-acetic anhydride furnished pyridobenzoxazinones (8) and isoquinolinobenzoxazinones (9) respectively in quantitative yields. Conversion of o-formylhomophthalanilic acid (7) to isocoumarinoquinoline (11) via 2-axo-3(o-carboxyphenyl)quinoline (10) is also described.     

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.     

Synthetic Application of Partially Protected Fructopyranoses

Partial deacetonation of 1-O-benzoyl-2,3:4,5-di-O-isopropylidene-β-D-fructopyranose (2) yielded the related 2,3-O-isopropylidene derivative (3) that was subsequently transformed into the corresponding 1-O-benzoyl-4,5-O-dibutylstannylene-2,3-O-isopropylidene-β-D-fructopyranose (4). Reaction of 4 with benzyl bromide proceeded with high regioselectivity to afford 1-O-benzoyl-5-O-benzyl-2/3-O-isopropylidene-β-D-fruc-topyranose (5) together with a small quantity of the 4-O-benzyl derivative (6). Oxidation of 5 gave the 4-oxo derivative (10) which was reduced to yield a mixture of 5 and its 4-epimer (11). Debenzylation of 11, followed by a debenzoylation reaction produced 2,3-O-isopropylidene-β-O-tagatopyranose (13). Aceto-nation of 13 yielded 1,2:3,4-di-O-isopropylidene-α-D-tagatofuranose (14). Structures and configurations of the above compounds were established on the basis of their analytical and spectroscopic data.     

Synthesis of the Oligosaccharide Moieties of Musettamycin,Marcellomycin and Aclacinomycin A,Antitumor Antibiotics

Abstract

Condensation of benzyl 2,3,6-trideoxy-3-trifluoroacetamido-α-L-lyxo-hexopyranoside (5) with 4-O-acetyl-3-O-benzyl-2,6-dideoxy-α-L-lyxo-hexopyranosyl bromide (10) carried out under Koenigs-Knorr conditions gave 12. Total deprotection of 12 and N-dimethylation at C-3 led to 17 while selective removal of the 4-O-acetyl group led to 13, a synthetic intermediate for preparing 24 and 33. Condensation of 13 with di-O-acetyl-L-fucal (18) or 4-O-acetyl-L-amicetal (25) in the presence of N-iodosuccinimide followed by hydrogenolysis of the C-2-I bond gave 20 and 27 respectively. The trisaccharide 24 then was obtained from 20 by the same sequence of reactions used to convert 12 into 17. After deacetylation and oxidation, this set of reactions also transformed 27 into 33.     

Photochemical Reactions in Carbohydrate Synthesis. Conversion of L-Arabinose Into L-Streptose

Abstract

A synthesis for L-streptose (1) is described. This synthesis differs from those previously reported in several ways, one of which is the use of photochemical reactions in two important steps. These reactions are part of a sequence leading from L-arabinose (2) to 5-deoxy-1,2-O-isopropylidene-β-L-threo-pentofuranos-3-ulose (3). Two other photochemical reactions are considered as a part of the conversion of 3 into L-streptose (1) but neither proved useful. L-Streptose (1) is synthesized from 3 by a sequence of reactions which involves formation of 5-deoxy-l,2-O-isopropylidene-3-C-nitromethyl-β-L-lyxo-furanose (10) and subsequent reaction of 10 with titanium(III) chloride.     

Six-Membered Nitrogen Heterocycles from Xylaramide and Ribaramide

Abstract

N,N'-Diacetyl-tri-O-acetylxylaramide (8) and N,N'-diacetyl-tri-O-acetylribaramide (20) were directly converted to the nitrogen heterocycle 6-acetamido-2,6-diacetyloxy-aza-1,4-cyclohexadlen-3-one (9) with sodium acetate in acetic anhydride. Treatment of tri-O-acetylxylaramide (7) or tri-O-acetylribaramide (19) with the same solvent-base combination gave the highly crystalline 2,3,5,6-tetraacetyloxypyridlne (30) as the principal product. Mechanistic considerations for the formation of these nitrogen heterocycles are presented.     

Synthesis of Retro-γ-Ionols and the Corresponding-Ionones1

Both the direct² and the sensitized^3,4 photolyses of (E)-β-ionol (2) have been studied in some detail. In a preliminary publication⁵ we have indicated that direct photolyses of (E)-β-ionol (2) with λ = 254 nm yields (Z)-retro-γ-ionol (3) as the primary product; upon further irradiation 3 is converted into the corresponding (E)-isomer (4) which rapidly yields the bicyclic alcohol 5. A quantitative study revealed that the photoconversion of (E)-β-ionol with λ = 254 nm to 3 is about 10 times faster than the conversion of 3 into (E)-retro-γ-ionol.⁶ This rate difference thus allows the photosynthesis of 3.     

Synthesis of the Four Configurational Isomers of N-Benzoyl-2, 3, 6-Trtdeoxy-3-C-Methyl-3-Amino-L-Hexose from the (2S, 3R)-Diol Obtained from α-Methylcinnamaldehyde by Fermentation with Baker'S Yeast

Abstract

The erythro and threo chiral C₅ methyl ketones (4) and (5), prepared from the (2S, 3R)-methyl diel (1b), were converted into the phenylsulfenimines (6) and (7), which, in turn, on reaction with allyl-magnesiutn bromide, yielded after acid hydrolysis and benzoylation, the diastereoisomeric C₈-N-aminodiol derivatives (9) and (11), with threo stereochemistry relative to positions 4 and 5. Ozonolysis of (9) and (11) yielded the l-arabino and l-xylo 3-O-methyl branched aminodeoxysugar derivatives (13) and (15), respectively. Using diallylzinc as the reagent, the diastereoisomeric erythro products (8) and (10) were obtained. The latter materials gave the l-ribo-and l-lyxo-(lL-vancosamine) derivatives (12) and (14) upon oxonolysis. The ¹H and ¹³C NMR spectra of the four isomeric aminodeoxysugar derivatives (12)—(15) were discussed.     

CHLOROSULFONATION OF N-PHENYLMORPHOLINE,BENZOTHIAZOLE, 2-METHYL BENZOTHIAZOLE AND TRIPHENYLOXAZOLE

Abstract

N-Phenylmorpholine (1) reacted with chlorosulfonic acid to give the p-sulfonyl chloride (2), which was characterized as the sulfonamides (3–5). Benzothiazole (6) was converted into the sulfonyl chloride (7) by sequential treatment with hot chlorosulfonic acid and thionyl chloride. Reaction of (7) with amines afforded the derivatives (8–10); NMR spectral analysis of the dimethylamide (8) indicated that it was a mixture of the 4- and 7-isomers. Chlorosulfonation of 2-methylbenzothiazole (11) was achieved by heating with chlorosulfonic acid with or without thionyl chloride. The chloride (12) was converted into amides (13–19). Study of the NMR spectra indicated that mixtures of the 5- and 6-isomers were formed. 2,4,5-Triphenyloxazole (20) reacted with chlorosulfonic acid to give either the mono-(21), bis (23) or bis-tris sulfonylchlorides (23, 34); these were converted into 14 sulfonamides. 2-(p-Nitrophenyl)-4,5-diphenyloxazole (41) reacted with hot chlorosulfonic acid to give the bis-sulfonyl chloride (42), characterized as the dimethylsulfonamide (43). Attempts to form the pure monosulfonyl chloride and to mono nitrate 2,4,5-triphenyloxazole (20) were unsuccessful.     

Aminohaloborane in Organic Synthesis. V.1 An Aldol-Type Condensation of Acetonitrile and Phenylacetonitrile with Benzaldehydes Using Secondary Aminodichloroborane

3-Phenyl-3-sec-aminopropionitriles (1) are not found in literature. We describe here a simple synthesis of 1 from acetonitriles (2) and benzaldehydes (3) using sec-aminodichloroboranes (4)² and triethylamine (5).     

Synthesis of C-Glycosyl α-Glycines

Abstract

A scheme of asymmetric synthesis of C-glycosyl α-glycines is described. Reductive hydrolysis of 2-deoxy-3,5-di-O-p-toluoyl-β D-erythropentofuranose 1-cyanide (4) in the presence of N,N-diphenylethylenediamine gave the imidazolidine 5, which was converted to 2,5-anhydro-3-deoxy-4,6-di-O-p-toluoyl-β-D-allose (3)by acid hydrolysis. The aldehyde (3), chiralamine, benzoic acid and t-butyl isocyanide four component condensation afforded in good yield two diastereomeric adducts (6a and 6b), which were separated by column chromatography and deblocked to furnish 2-deoxy-β-D-erythropentofuranosyl R and S-glycines (1a) and (1b).     

Reactions of a New Type of Intermediate Formed by Triflate Rearrangement

Treatment of methyl 4-O-benzoyl-2, 6-dideoxy-β-D-arabino-hexopyranoside (6) with triflic anhydride in The presence of 2, 6-di-t-butyl-4-methylpyridine (7) produces methyl 4-O-benzoyl-2, 6-dideoxy-3-O-(tri-fluoromethylsulfonyl) -β-D-arabino-hexopyranoside (8), a compound which rearranges to a new and highly unstable triflate (10) upon standing at room temperature. Bromide ion reacts with 10 to give methyl 4-O-benzoyl-3-bromo-2,3,6-trideoxy-β-D-arabino-hexopyranoside (11), a product of displacement at C-3. A similar reaction takes place with nitrate ion to give methyl 4-O-benzoyl-2, 6-dideoxy-3-O-nitro-β-D)-arabino-hexopyranoside (15). Reaction of 10 with water and with tributyltin hydride results in capture of the cation 12, formed by ionization of 10, to give methyl 3-O-benzoyl-2,6-dideoxy-β-D-ribo-hexopyranoside (14) and methyl 3, 4-O-benzylidene-2, 6-dideoxy-β-D-ribo-hexopyranosi de (16), respectively. The cation 12 also reacts with methanol to afford the orthobenzoates 17 and 18.     

Synthesis of 2′,3′-Dideoxy-2′-Fluorokanamycin A

2′,3′-Dideoxy-2′-fluorokanamycin A (23) was prepared by condensation of 6-azido-4-0-benzoyl-2,3,6-trideoxy-2-fluoro-α-D-ribo-hexopyranosyl bromide (13) and a protected disaccharide (19). Methyl 4,6-0-benzylidene-3-deoxy-β-D-arabino-hexopyranoside (5) prepared from methyl 4,6-0-benzylidene-3-chloro-3-deoxy-β-D-allo-hexopyranoside (1) by oxidation with pyridinium chlorochromate followed by reduction with Na₂ S₂O₄ was fluorinated with the DAST reagent to give methyl 4,6-O-benzylidene-2,3-dideoxy-2-fluoro-β-D-ribo-hexopyranoside (7). Successive treatment of 7 with NBS, NaN₃ and SOBr₂ gave 13. The structure of the final product (23) was determined by the ¹H and ¹⁹F and shift-correlated 2D NMR spectra.     

Diborane Reduction of O-(Tert-Butyldimethylsilyi.)galactaramides. A Model Study for Aminoalditol Synthesis

Tert-butyldimethylsilylation of dimethyl galactarate (1) with tert-butylchlorodimethylsilane/imidazole/N,N-dimethylformamide at 25 [ddot]C dimethyl 2,5-bis-O-(tert-butyldimethylsilyl)galactarate (2) as the principal product, with methyl 2,3,5-tris-O-(tert-butyldimethylsilyl)-D,L-galactarate-l,4-lactone (3) and methyl 2,3-bis-O-(tert-butyldimethyl)-D,L-galactarate-l,5-lactone (4) as minor products. When the reaction was carried out at 65 [ddot]C, the only product was the 1,4-lactone, 3 Ammonolysis of 2 in methanol gave 2,5-bis-O-(tert-butyldimethyl)-galactaramide (5, 94%), which was conveniently reduced with borane- THF to 1,6-diamino-1,6-dideoxygalactitol, isolated as its dihydrochloride 9. Ammonolysis of 3 in methanol gave a mixture of 5; 2,3,4-tris-O-(tert-butyldimethylsilyl)-D,L-galactaramide (6), 2,3,5-tris-O-(tert-butyldimethylsilyl)-D,L-galactaramide (7), and 2,3,5-tris-Q-(tert-butyldimethylsilyl)-D,L-1,4-lactonogalactaramide (8). Borane-THF reduction of a mixture of 6 and 7 also yielded 9. This study served as a model for the use of O-silylated carbohydrate amides in the preparation of aminodeoxyalditols.     

An Unusual Aminal Derivative from a Misdirected Gabriel Synthesis

N-(2-Bromoethyl)phthalimide (1) was reacted with sodium imidazolate in DMF to give the novel aminal N-[1-(1H-imidazol-1-yl)ethyl]phthalimide (4a) as well as N-vinylphthalimide (3) and the desired Gabriel intermediate 2. Aminal 4a as well as heterologues 4b - d form directly from reaction of 3 with the appropriate heterocyclic sodium salt.     

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 Convenient Synthesis of (Z)-7-Nonadecen-Ll-One and (Z)-7-Eicosen-Ll-Cne -the Pheromones of Peach Fruit Moth

In 1977 Tamaki¹ et al have isolated and synthesized² (Z)-7-nonadecen-ll-one (la) and (Z)-7-eicosen-l1-one (1b) which are active components of the female sex pheromones of the peach fruit moth Carposina niponensis Walsingham, a major economic pest of apple, peach and other fruits of Japan. We report in this communication a practical, convenient and stereospecific route to 1a and 1b.     

A General Method for Stepwise Elongation of the (1→5)-α-D-Arabinofuranan Chain

Condensation reaction of 3,5-di-O-benzoyl-1,2-O-(1-cyanoben-zylidene)-β-D-arabinofuranose (2) with benzyl and allyl 2,3-di-O-benzoyl-5-O-triphenylmethyl-α-L-arabinofuranosides (5a and 5b) in methylene chloride in the presence of triphenylcarbenium tetrafluoroborate as catalyst under high vacuum gave α-(1→5)-linked dimeric D-arabinofuranoside derivatives (6a and 6b). One of the dimeric compounds (6a) was debenzoylated, triphenylmethylated, and rebenzoylated to give a dimeric homolog of 5a (8). Similarly for the preparation of 6a, 8 was condensed with 2 to provide an α-(1→5)-linked trimeric D-arabinofuranoside derivative (9). Further elongation of the glycoside chain might be possible in the same way.     

Synthesis of Glycosyl Cyanides and C-Allyl Glycosides by the use of Glycosyl Fluoride Derivatives

A treatment of 2,3,5-tri-O-benzyl-B-D-ribofuranosyl fluoride (1) with cyanotrimethylsilane in the presence of boron trifluoride diethyl etherate gave 2,3,5-tri-O-benzyl-α- (2α) and -β-D-ribofuranosyl (2β) cyanide in 46.2% and 46.6% yields, respectively. Confirmation of the corresponding isocyano isomer (3) formation and its conversion into 2 under boron trifluoride catalysis at -78°C made it possible to deduce that both 2α and 2β were produced by way of 3 which was formed preponderantly in the initial stage of the reaction. On the other hand, the reaction of 2,3,4,6-tetra-O-benzyl-α-D-glucopyranosyl fluoride (4) with cyanotrimethylsilane in diethyl ether by the use of boron trifluoride diethyl etherate (0.05 mol. equiv.) gave 2,3,4,6-tetra-O-benzyl-α -D-glucopyranosyl cyanide (5α), 2,3,4,6-tetra-O-benzyl-α- (6α), and -β-D-glucopyranosyl isocyanide (6β) as a 30:61:9 mixture (94% yield) but that in dichloromethane by the use of the catalyst (1.0 mol. equiv.) gave 5α (85% yield) as a sole product.

The reactions of 1 and of 4 with allyltrirnethylsilane under the same catalysis afforded C-allyl 2,3,5-tri-O-benzyl-α-D-ribofuranoside (7)(93.5% yield), and C-allyl 2,3,4,6-tetra-O-benzyl-α- (8α)(71.8% yield) and -β-D-glucopyranoside (8β) (22.4% yield), respectively.     

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.