Synthesis of polyalkyl-1-tetralones and the corresponding naphthalenes

Abstract

The stepwise synthesis of specifically substituted trialkyl-3,4-dihydro-l (2H >naphthalenones (1-tetralones), the corresponding naphthalenes, and partially hydrogenated derivatives, several having the cadalene-type 1,4,6 substitution, has been reexamined. Individual steps have been improved and new approaches with fewer steps and higher overall yields have been devised. Syntheses utilizing lactones in Friedel-Crafts reactions were also carried out. These latter Friedel-Crafts reactions are responsible for rearrangements during tetralone syntheses which were previously attributed to polyphosphoric acid during cyclization.The synthesis of cadalene (1) became important to us as a route to pure polyalkylnaphthalenes and as a (1) E.

Enolization in radical cations of o-methylacetophenone and related species under cryogenic conditions

“…(4), where izing the width of activation energy distributions [eqn. (6)] are given in Table 1 together with the kinetic parameters used in the nL 6 (6) o2 = -[(l -a)RT/aI2 fitting procedure. For 1 and ['H3]-1 these parameters were calculated assuming that the absorption observed just after the pulse corresponds to the reaction progress during the time of the pulse duration.…”

The conformational diastereomers of 7-substituted-(8Z)-8-chloro-6,7-dihydro-9-(1,2-dihydro-6-R-naphthalen-4-yl)-2-R-5H-benzo[7]annulene, the question of atropisomerism versus ring inversion

“…25 Cyclization of 6 by treatment of polyphosphoric acid (PPA) gave 26 7-substituted 3,4-dihydronaphthalen-1(2H)-one 7a, 7b that were converted to the pinacol 8 (1,2,3,4-tetrahydro-1-(1,2,3,4-tetrahydro-1-hydroxynaphthalen-1-yl)naphthalen-1-ol 8a and its derivative 8b) with amalgamated aluminum foil in alcohol-benzene according to the procedure described by Newman. 27 The pinacol 8 was isolated as a mixture of crystals.…”

A one-step efficient general method for the synthesis of naphthopyrones: A first synthesis of spiro [naphthalene-2,4′-phenanthrene] carbocycles

“…2.9- 3,5,pyran-4-one (5e): 7-Methyl-l-tetralone (Eisenbraun et al 1971) 2g, 04)13 mol) reacted with crotonic acid (2"4 g, 0"028 mol) in PPA (20 g). Elution of the ehromatogram with pet.…”