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.

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. 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.

Pulse polarographic study of the behaviour of some o,o'-dihydroxyazo-compounds

1989 ◽  
Vol 54 (5) ◽  
pp. 1219-1226 ◽  
Author(s):  
Enric Casassas ◽  
Miquel Esteban ◽  
Santiago Alier
Keyword(s):  
Carboxylic Acid ◽  
Reaction Mechanisms ◽  
Sulphonic Acid ◽  
Base Catalysis ◽  
Polarographic Study ◽  
Acid Base ◽  
Eriochrome Black T ◽  
Naphthoic Acid ◽  
Calcon Carboxylic Acid

The reduction of several o,o'-dihydroxyazo-compounds is studied by means of pulse polarographic techniques (DPP, NPP and RPP). The compounds studied are the following: 2-(2'-hydroxyphenylazo)-phenol (o,o'-dihydroxyazobenzene), 1-(2'-hydroxy-1'-naphthylazo)-2-naphthol-4-sulphonic acid (calcon or Eriochrome Blue Black R), 1-(2'-hydroxy-4'-sulpho-1'-naphthylazo)-2-hydroxy-3-naphthoic acid (calcon carboxylic acid), and 1-(1'-hydroxy-2'-naphthylazo)-6-nitro-2-naphthol-4-sulphonic acid (Eriochrome Black T). Correlations between Ip and Epand experimental variables (pH, T, conc.) and instrumental parameters (dropping time, t, and pulse magnitude, ΔE) are established. Reaction mechanisms formerly proposed are discussed on the basis of the new obtained results, and the ranges are defined where adsorption and/or acid-base catalysis are operative.

Cyclization of 2-(2-bromoethoxy)-acetophenones and 5-(ω-haloalkoxy)-1,5-dihydro-2H-pyrrol-2-ones – Formation of five- to eight-membered oxygen-containing heterocycles via intramolecular alkylation

2004 ◽  
Vol 82 (5) ◽  
pp. 571-578 ◽  
Author(s):  
Kirill V Nikitin ◽  
Nonna P Andryukhova
Keyword(s):  
Sodium Hydride ◽  
Spiro Compounds ◽  
Lithium Diisopropylamide ◽  
Intramolecular Alkylation ◽  
High Yields

Under basic conditions (lithium diisopropylamide or sodium hydride in THF) 2-(2-bromoethoxy)-acetophenones were transformed to 3,4-dihydro[1]benzoxepin-5(2H)-ones (homochromanones) in high yields. The preparation of novel tetrahydropyrano[2,3-b]pyrrol-6(2H)-ones and 3,4-dihydro-2H-pyrrolo[2,1-b][1,3]oxazin-6(8aH)-ones and spiro compounds was performed using similar cyclization in moderate to good yields.Key words: cyclization, lithiation, spiro heterocycles.

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