Regulators of cell division in plant tissues. VII. The synthesis of zeatin and related 6-substituted purines

1969 ◽  
Vol 22 (1) ◽  
pp. 205 ◽  
Author(s):  
DS Letham ◽  
RE Mitchell ◽  
T Cebalo ◽  
DW Stanton
Keyword(s):  
Zea Mays ◽  
Cell Division ◽  
Acid Hydrolysis ◽  
Sodium Borohydride ◽  
Aluminium Chloride ◽  
Plant Tissues ◽  
Lithium Aluminium Hydride ◽  
Lithium Aluminium

6-(4-Hydroxy-3-methylbut-trans-2-enylamino)purine (zeatin), a cytokinin isolated from Zea mays, has been synthesized by a new route. β- Methylcrotononitrile was brominated with N-bromosuccinimide yielding γ- bromo-β-methylcrotononitrile, from which trans-γ-acetoxy-β- methylcrotononitrile was prepared. The alcohol derived from this acetate was converted into trans-β-methyl-γ-(tetrahydropyran-2- yloxy)crotononitrile. Reduction and acid hydrolysis gave 4-amino-2- methylbut-trans-2-en-1-ol which was made to react with 6-chloropurine to yield zeatin. ��� Several γ-alkoxy-β-methylcrotononitriles were prepared and reduced by aluminium chloride-lithium aluminium hydride to the corresponding unsaturated amines. Saturated nitrile formation also occurred in these reductions. The amines prepared were condensed with 6-chloropurine to yield a series of O-alkylzeatins. A number of other zeatin analogues were also synthesized. Two 6-methoxyalkylamino-purines were cleaved by sodium borohydride in the presence of iodine to 6-hydroxy- alkylaminopurines.

The synthesis of Cyclododecane-r-1,c-5,c-9-triamine and r-1,c-5,c-9-Tris(2,3-dimethoxybenzamido)cyclododecane

1975 ◽  
Vol 28 (3) ◽  
pp. 673 ◽  
Author(s):  
DJ Collins ◽  
C Lewis ◽  
JM Swan
Keyword(s):  
Aqueous Solution ◽  
Acid Hydrolysis ◽  
Sulphuric Acid ◽  
Sodium Carbonate ◽  
Sodium Azide ◽  
Room Temperature ◽  
Dimethyl Formamide ◽  
Lithium Aluminium Hydride ◽  
Lithium Aluminium ◽  
Hydrolysis Of

Treatment of cyclododecane-r-1,c-5,c-9-triyl tris(p-toluenesulphonate) with sodium azide in dimethyl-formamide at 100� for 6 h gave the corresponding cis,cis-triazide which upon hydrogenation or reduction with lithium aluminium hydride gave cyclododecane-r-1,c-5,c-9-triamine, isolated as the tris-salicylidene derivative. Acid hydrolysis of this, removal of the salicylaldehyde, and treatment of the aqueous solution with sodium carbonate and 2,3-dimethoxybenzoyl chloride gave r-1,c-5,c- 9-tris(2,3-dimethoxybenzamido)cyclododecane. ��� Treatment of (E,E,E)-cyclododeca-1,5,9-triene with an excess of acetonitrile and sulphuric acid at room temperature for three days gave 18% of (E,E)-1-acetamidocyclododeca-4,8-diene; no di- or tri-amides were isolated.

Flavan derivatives. XXIII. Preparation and synthetic applications of Flav-3-enes

1968 ◽  
Vol 21 (9) ◽  
pp. 2247 ◽  
Author(s):  
JW Clark-Lewis ◽  
RW Jemison
Keyword(s):  
Sodium Borohydride ◽  
Acidic Medium ◽  
Catalytic Reduction ◽  
Heterocyclic Ring ◽  
High Yield ◽  
Lithium Aluminium Hydride ◽  
Lower Field ◽  
Field Characteristic ◽  
Lithium Aluminium ◽  
New Synthesis

2'-Hydroxychalcones and α-alkoxy-2'-hydroxychalcones are converted by sodium borohydride in isopropanol into flav-3-enes and 3-alkoxyflav-3-enes in the convenient new synthesis which makes these flavenes readily available. Catalytic reduction of the flavenes gives the corresponding flavans or 3-alkoxyflavans in high yield, and the latter are obtained mainly in the 2,s-cis-form. The flavenes immediately give flavs lium cations in the cold when treated with acids in air, and oxidation of 5,7,3',4'-tetramethoxyflav-3-ene with benzoquinone in an acidic medium gave the flavylium salt, isolated as the ferrichloride. Reduction of 5,7,3',4'-tetramethoxy-flavylium chloride with lithium aluminium hydride gave 5,7,3',4'-tetramethoxy-flav-2-ene identical with the flavene obtained from (-)-epicatechin tetramethyl ether, and confirms an earlier investigation by Gramshaw, Johnson, and King. In its N.M.R. spectrum the heterocyclic-ring protons of this flav-2-ene give an ABX multiplet which is easily distinguished from the ABX multiplet at much lower field characteristic of flav-3-enes.

Reaction of 3,4a-disubstituted 4,4-dimethyl-5,6β-epoxy-A-homo-5β-cholestane derivatives with reducing agents

1985 ◽  
Vol 50 (11) ◽  
pp. 2457-2470 ◽  
Author(s):  
Helena Velgová ◽  
Jaroslav Zajíček
Keyword(s):  
Sodium Borohydride ◽  
Reducing Agents ◽  
Epoxide Ring ◽  
Lithium Aluminium Hydride ◽  
H Nmr ◽  
Lithium Aluminium ◽  
Nmr Data ◽  
Epoxy Alcohols

Reaction of all stereoisomeric 3-acetoxy-4,4-dimethyl-5,6β-epoxy-A-homo-5β-cholestan-4a-ols I-IV with lithium aluminium hydride and reduction of 3-acetoxy-4,4-dimethyl-5,6β-epoxy-A-homo-5β-cholestan-4a-ones XXII and XXIII with sodium borohydride were studied. It was found that reductive opening of the 5β,6β-epoxide ring occured only in the case of the derivatives III and IV due to 5(O)n participation of the 3α-oxygen-containing substituent under formation of the transannular 3α,5α-epoxides VIII and IX, resp. On reduction of the 4a-keto epoxides XXII and XXIII with sodium borohydride the trans-epoxy alcohols III and I were formed. On the basis of 1H NMR data the conformation of the A-ring in the epoxides I-IV, XXII, and XXIII is also discussed.

4,5-Seco-4,6-cyclosteroids. II. Synthesis of 4,5-Seco-4,6-cyclo-6β-cholestan-5α-ol

1969 ◽  
Vol 22 (3) ◽  
pp. 627
Author(s):  
DJ Collins ◽  
JJ Hobbs ◽  
RJ Rawson
Keyword(s):  
Methyl Ester ◽  
Acid Hydrolysis ◽  
Acid Methyl Ester ◽  
Lithium Aluminium Hydride ◽  
Lithium Aluminium ◽  
Acid Methyl ◽  
Successive Reduction ◽  
Ethylene Acetal

5-oxo-4,5-secocholestan-4-oic acid methyl ester (XIIIb) was converted into the corresponding cyclic ethylene acetal (XIVb) which, upon successive reduction with lithium aluminium hydride and acid hydrolysis, gave 4-hydroxy-4,5-secochol-estan-5-one (XVa), converted into the tosyl ester (XVb). Base-catalysed intra-molecular alkylation of the latter gave mainly A-homo-4a-oxacholest-5-ene (XVII), together with 4,5-seco-4,6-cyclo-6β-cholestan-5-one (IIIc), reduced with lithium aluminium hydride to 4,5-seco--1,6-cyclo-6β-cholestan-5α-ol (IIb). This was identical with material previously prepared by transformation of 4,5-seco-4,6-cyclo-6β-cholestane-3β,5α-diol (IIa), obtained from reductive rearrangement of 6β-bromo-4β,5-epoxy-5,β-cholestan-3β-ol (I). ��� Some other approaches to the synthesis of 4,5-seco-4,6-cyolo-6β- cholestane derivatives are described.

Synthesis and stereochemistry of 1-Thiaflavan-4-ols

1966 ◽  
Vol 19 (7) ◽  
pp. 1251 ◽  
Author(s):  
GF Katekar
Keyword(s):  
Sodium Borohydride ◽  
Nitrous Acid ◽  
Lithium Aluminium Hydride ◽  
Lithium Aluminium

Lithium aluminium hydride or sodium borohydride reduced 1-thiaflavanone, 6-methyl-1-thiaflavanone, and 4'-chloro-1-thiaflavanone to the corresponding 2,4-cis-1-thiaflavan-4-ols. Deamination of 2,4-cis-4-amino-1-thiaflavans with nitrous acid gave rise to the 2,4-trans-1-thiaflavan-4-ols. N.m.r. measurements were used to determine the stereochemistry of these compounds.

Utilization of 1,6-anhydrohexoses for the preparation of some aliphatic adenosine analogs

1989 ◽  
Vol 54 (10) ◽  
pp. 2753-2766 ◽  
Author(s):  
Marcela Krečmerová ◽  
Miloslav Černý ◽  
Miloš Buděšínský ◽  
Antonín Holý
Keyword(s):  
Hydrochloric Acid ◽  
Sodium Borohydride ◽  
Sodium Salt ◽  
Dilute Hydrochloric Acid ◽  
Lithium Aluminium Hydride ◽  
Subsequent Reduction ◽  
Adenosine Analogs ◽  
Lithium Aluminium

Reaction of sodium salt of adenine with 1,6:3,4-dianhydro-2-O-p-toluenesulfonyl-β-D-galactopyranose (I) afforded 4-(adenin-9-yl)-1,6:2,3-dianhydro-4-deoxy-β-D-mannopyranose (II) and 2,4-bis(adenin-9-yl)-1,6-anhydro-2,4-dideoxy-β-D-glucopyranose (IV). Compound II was converted into 4-(adenin-9-yl)-1,6-anhydro-4-deoxy-β-D-glucopyranose (VI). Cleavage of the 1,6-anhydro bond in this compound with hot concentrated hydrochloric acid led to 4-(adenin-9-yl)-4-deoxy-D-glucose (VIII) which was reduced with sodium borohydride to give 4-(adenin-9-yl)-4-deoxy-D-glucitol (IX). Epoxide II was reduced with lithium aluminium hydride and the obtained 4-(adenin-9-yl)-1,6-anhydro-2,4-dideoxy-β-D-arabinohexopyranose (VII) on treatment with dilute hydrochloric acid and subsequent reduction with sodium borohydride gave 4-(adenin-9-yl)-2,4-dideoxy-D-arabino-hexitol (XI).

HYDROGENOLYSIS BY LITHIUM ALUMINIUM HYDRIDE – ALUMINIUM CHLORIDE OF ETHER SOLUTIONS OF CAMPHOR ETHYLENE KETAL AND NORCAMPHOR ETHYLENE KETAL

1966 ◽  
Vol 44 (13) ◽  
pp. 1547-1550 ◽  
Author(s):  
W. W. Zajac Jr. ◽  
B. Rhee ◽  
R. K. Brown
Keyword(s):  
Reductive Cleavage ◽  
Aluminium Chloride ◽  
Lithium Aluminium Hydride ◽  
Similar Reduction ◽  
Lithium Aluminium

The lithium aluminium hydride – aluminium chloride reductive cleavage of norcamphor ethylene ketal yields 2-(2-endo-norbornyloxy)ethanol in ≥98% yield, whereas the similar reduction of camphor ethylene ketal gives 2-(2-isobornyloxy)ethanol in 78% yield and 2-(2-bornyloxy)ethanol in 22% yield. These are the products arising from steric approach control.

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