Studies on intramolecular alkylation. I. The preparation of tricyclic intermediates for the synthesis of diterpene alkaloids

1971 ◽  
Vol 24 (2) ◽  
pp. 343 ◽  
Author(s):  
DJ Beames ◽  
LN Mander
Keyword(s):  
Diterpene Alkaloids ◽  
Intramolecular Alkylation ◽  
Standard Procedures ◽  
Naphthoic Acid ◽  
Diastereomeric Mixture

The tricyclic dienones (14), (16), and (16) have been prepared by the Ar1-6 cyclization of a diastereomeric mixture of 7-[(2?-bromo-1?- tetrahydropyranyloxy)-ethyl]-5,6,7,8-tetrahydro-2-naphthols (11) and of 7-diazoacetyl-5,6,7,8-tetrahydro-2-naphthol (17). Intermediates (11) and (17) were prepared by standard procedures from 1,2,3,4-tetrahydro- 7-hydroxy-2-naphthoic acid.

Studies on intramolecular alkylation. X. The acid-catalysed reactions of 5,8-Dialkoxy-1,2,3,4-tetrahydronaphthyl diazomethyl ketones

1978 ◽  
Vol 31 (7) ◽  
pp. 1561 ◽  
Author(s):  
DW Johnson ◽  
LN Mander
Keyword(s):  
Trifluoroacetic Acid ◽  
Acid Treatment ◽  
Polyphosphoric Acid ◽  
Intramolecular Alkylation ◽  
Naphthoic Acid ◽  
Acid Catalysed Reactions ◽  
Diazomethyl Ketones

5,8-Dimethoxy-3,4-dihydronaphthalen-1(2H)-one was converted into diazomethyl 5,8-dimethoxy-1,2,3,4-tetrahydro-2-naphthyl ketone (10) which, when treated with trifluoroacetic acid at 0°, gave 5,8- dimethoxy-4,4a-dihydro-3,4a-ethanonaphthalen-2(3H)-one (13), but at -15° gave 8-methoxy-1,2,3,4-tetrahydro-3,4a-ethanonaphthalene- 5(4aH),10-dione (14). 6-Methoxy-3,4-dihydronaphtha-len-1(2H)-one reacted with m-chloroperoxybenzoic acid to give 4,5-dihydro-1-benzoxepin-2(3H)-one (15) which after hydrolysis, ethylation and polyphosphoric acid treatment gave 5-ethoxy-8-methoxy-3,4-dihydronaphthalen-1(2H)-one (17). This compound was transformed into 5-ethoxy-8-hydroxy-1,2,3,4-tetrahydro-2-naphthoic acid (19) and thence to the ethoxy analogue of (14).

Studies on intramolecular alkylation. VI. ortho-Alkylation in phenolic diazoketones: the preparation of intermediates containing the Cyclohexa-2,4-dienonemoiety suitable for gibberellin synthesis

1974 ◽  
Vol 27 (6) ◽  
pp. 1277 ◽  
Author(s):  
DW Johnson ◽  
LN Mander
Keyword(s):  
Intramolecular Alkylation ◽  
Naphthoic Acid ◽  
Acid Catalysed Reactions

Simple efficient syntheses of 8-hydroxy- and 8-methoxy-2-tetralones (9) and (10), 1,2,3,4-tetrahydro-8- hydroxy-2-naphthoic acid (5), 1,2,3,4-tetrahydro-2-hydroxy-8-methoxy-2-naphthoic acid (8), 1,2,3,4-tetrahydro-2,s-dihydroxy-2-naphthoic acid (7) and 1,2,3,4-tetrahydro-5-hydroxy-2-naphthoic acid (20) are described. The acid-catalysed reactions of the diazoketones derived from (5) and (20) gave good yields of tricyclic ketones (3) and (4) incorporating a cyclohexa-2,4-dienone moiety. The potential of (3) for gibberellin synthesis is examined.

Studies on intramolecular alkylation. IX. The synthesis of tricyclic dienones suitable for the synthesis of 13-hydroxygibberellins

1978 ◽  
Vol 31 (2) ◽  
pp. 405 ◽  
Author(s):  
IA Blair ◽  
A Ellis ◽  
DW Johnson ◽  
LN Mander
Keyword(s):  
Intramolecular Alkylation ◽  
Naphthoic Acid

2-Hydroxy-6-methoxy-1,2,3,4-tetrahydro-2-naphthoic acid and its 8- methoxy isomer were converted into trichloroacetate and dichloroacetate derivatives and thence to diazoketones (2), (3), (12) and (13). The acid-catalysed cyclization of these substrates to the dienones (6), (7), (16) and (17), respectively, was then studied. The trichloroacetoxy derivatives gave the best yields of dienones.

Effect of Niacin on Mitochondria of Allium Cepa Root Cells

1967 ◽  
Vol 25 ◽  
pp. 78-79
Author(s):  
M. Arif Hayat
Keyword(s):  
Nicotinamide Adenine Dinucleotide ◽  
Hydrogen Transfer ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Nicotinamide Adenine ◽  
Root Tips ◽  
Root Cells ◽  
Transfer Processes ◽  
Standard Procedures ◽  
A Cell ◽  
Critical Interest

Although it is recognized that niacin (pyridine-3-carboxylic acid), incorporated as the amide in nicotinamide adenine dinucleotide (NAD) or in nicotinamide adenine dinucleotide phosphate (NADP), is a cofactor in hydrogen transfer in numerous enzyme reactions in all organisms studied, virtually no information is available on the effect of this vitamin on a cell at the submicroscopic level. Since mitochondria act as sites for many hydrogen transfer processes, the possible response of mitochondria to niacin treatment is, therefore, of critical interest.Onion bulbs were placed on vials filled with double distilled water in the dark at 25°C. After two days the bulbs and newly developed root system were transferred to vials containing 0.1% niacin. Root tips were collected at ¼, ½, 1, 2, 4, and 8 hr. intervals after treatment. The tissues were fixed in glutaraldehyde-OsO4 as well as in 2% KMnO4 according to standard procedures. In both cases, the tissues were dehydrated in an acetone series and embedded in Reynolds' lead citrate for 3-10 minutes.

Microstructure of Electro-Eroded Cemented Carbide Surfaces

1968 ◽  
Vol 26 ◽  
pp. 284-285
Author(s):  
V. N. Filimonenko ◽  
M. H. Richman ◽  
J. Gurland
Keyword(s):  
Surface Layer ◽  
Cobalt Content ◽  
Cemented Carbides ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
Metallographic Examination ◽  
Standard Procedures ◽  
Face Centered ◽  
Diamond Paste ◽  
Plastic Carbon

The high temperatures and pressures that are found in a spark gap during electrical discharging lead to a sharp phase transition and structural transformation in the surface layer of cemented carbides containing WC and cobalt. By means of X-ray diffraction both W2C and a high-temperature monocarbide of tungsten (face-centered cubic) were detected after electro-erosion. The W2C forms as a result of the peritectic reaction, WC → W2C+C. The existence and amount of the phases depend on both the energy of the electro-spark discharge and the cobalt content. In the case of a low-energy discharge (i.e. C=0.01μF, V = 300v), WC(f.c.c.) is generally formed in the surface layer. However, at high energies, (e.g. C=30μF, V = 300v), W2C is formed at the surface in preference to the monocarbide. The phase transformations in the surface layer are retarded by the presence of larger percentages of cobalt.Metallographic examination of the electro-eroded surfaces of cemented carbides was carried out on samples with 5-30% cobalt content. The specimens were first metallographically polished using diamond paste and standard procedures and then subjected to various electrical discharges on a Servomet spark machining device. The samples were then repolished and etched in a 3% NH4OH electrolyte at -0.5 amp/cm2. Two stage plastic-carbon replicas were then made and shadowed with chromium at 27°.

The early development of antenna and antennal sensilla in the noctuid moth, Agrotis segetum (Insecta: Lepidoptera)

1990 ◽  
Vol 48 (3) ◽  
pp. 502-503
Author(s):  
Eric Hallberg ◽  
Lina Hansén
Keyword(s):  
Cell Death ◽  
Stem Cell ◽  
Early Development ◽  
Larval Stage ◽  
Pupal Stage ◽  
Agrotis Segetum ◽  
Antennal Sensilla ◽  
Noctuid Moth ◽  
Standard Procedures

The antennal rudiments in lepidopterous insects are present as disks during the larval stage. The tubular double-walled antennal disk is present beneath the larval antenna, and its inner layer gives rise to the adult antenna during the pupal stage. The sensilla develop from a cluster of cells that are derived from one stem cell, which gives rise to both sensory and enveloping cells. During the morphogenesis of the sensillum these cells undergo major transformations, including cell death. In the moth Agrotis segetum the pupal stage lasts about 14 days (temperature, 25°C). The antennae, clearly seen from the exterior, were dissected and fixed according to standard procedures (3 % glutaraldehyde in 0.15 M cacaodylate buffer, followed by 1 % osmiumtetroxide in the same buffer). Pupae from day 1 to day 8, of both sexes were studied.

C18 diterpene alkaloids from Aconitum toxicum Rchb.

Planta Medica ◽  
2007 ◽  
Vol 73 (09) ◽  
Author(s):  
D Csupor ◽  
P Forgo ◽  
K Csedő ◽  
J Hohmann
Keyword(s):  
Diterpene Alkaloids

Soil Sampling Procedures

EDIS ◽  
2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
Davie Kadyampakeni ◽  
Kelly Morgan ◽  
Arnold Schumann ◽  
Rhuanito Ferrarezi ◽  
Jamie D Burrow
Keyword(s):  
Soil Sampling ◽  
Test Results ◽  
Fertilization Program ◽  
Fact Sheet ◽  
Standard Procedures ◽  
Sampling Procedures ◽  
Soil And Water

To achieve optimal grove nutrition, citrus growers must test grove soil before beginning any fertilization program. Standard procedures for sampling, preparing, and analyzing soil should be followed for meaningful interpretations of the test results and accurate recommendations. This new two-page fact sheet, published by the UF/IFAS Department of Soil and Water Sciences, provides illustrated soil sampling procedures and tables to aid in basic interpretation of lab results. Written by Davie Kadyampakeni, Kelly Morgan, Arnold Schumann, and Rhuanito S. Ferrarezi.https://edis.ifas.ufl.edu/ss667

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