Tetrahydronaphthalene derivatives

Eriedel-Crafts reaction of naphthalene or tetrahydronaphthalene derivatives with those of styrene or alkylbenzenes has been used in the preparation of high viscous fluids for traction drive (195). Similarly, Eriedel-Crafts reaction of tetraline and a-methylstyrene followed by catalytic hydrogenation provided l-(l-decalyl)-2-cyclohexyl propane, which is used as a highly heat resistant fluid (196). 

With the above data, it is possible to establish the molecular formula, and, by proper analysis, combination, and correlation of these data with values for known pure compounds, to determine the type of hydrocarbons constituting the homogeneous mixture, as paraffin, cycloparaffin, dicycloparaffin, benzene derivative, naphthalene derivative, tetrahydronaphthalene derivative, etc. 

Of the tetrahydronaphthalene derivatives (III-VI) required for this work, all of the monosubstituted compounds (III and IV) are known. However, IVa and IV6 were prepared from 5,6,7,8-tetra-hydro-l-naphthoyl chloride by Rosenmund reduction and by reaction with dimethyleadmium, respectively, rather th n by previously published methods. 

Table 1. Frequencies (in cm 1) of the carbonyl absorption bands and Av(C O) values (in cmr ) for the tetrahydronaphthalene derivatives in 0 02. M carbon...

The lignenolide (XXVII) may undergo a condensation between its double bond and position 2 or 6 of the other nucleus to form a cyclolignan, a tetrahydronaphthalene derivative which can give rise to benzenepenta-... 

Tetrahydronaphthalenic derivatives (new agonist and antagonist ligands for melatonin receptors)... 

For the dimerization of 4,4 -dimethoxystilbene, it has been possible to demonstrate spectroelectrochemically [115] and at the rotating ring-disk electrode [116] that the product is formed mainly by radical dimerization of the intermediate radical cations [path B, Eq. (13)]. Fast derivative CV, however, supports for the same olefin a complex ECE pathway [path A, Eq. (13) [117]. Depending on the oxidation potential and the kind of the nucleophiles (acetate, water, or methanol), a tetrahydronaphthalene derivative (Table 6, number 3) [118], a monomer diacetate [118], a tetrahydrofuran [115], or a dimer dimethoxy compound is found. When methanol is replaced by aqueous dichloromethane or by aqueous acetonitrile emulsions as solvent, styrene (Table 6, number 4) [119a] and a-methylstyrene [119b] yield 2,5-diphenyltetrahydrofurans. In some cases cyclization occurs by electrophilic aromatic substitution (analogous to Table 6, number 3). 

The Diels-Alder reaction to construct the molecular skeleton of the tetracyclic system was carried out by heating a mixture of 3,6-dimethoxybenzocyclobutene 30 and enone (+)-69 at 210-220°C for 10 h, giving the desired adduct (+)-70 in 40% yield (Scheme 14). The NMR spectrum of (+)-70 indicated that the product was composed of a single stereoisomer. Tetrahydronaphthalene derivative... 

The f-butylated naphthalene derivative (18 equation 49) is of interest as an intermediate for the synthesis of fungicides. Tetrahydronaphthalene derivatives, such as (20), have been evaluated as antifertility agents. Sugita et al. have studied the AlCb-catalyzed Friedel-Crafts alkylation of benzene with l-phenyl-2-propanol and 2-phenyl-1-propanol in the presence of additives, such as CuCb, CU2CI2 and decalin. Highly regioselective formation of 1,1-diphenylpropane was observed with Cu or Cu chloride as the additive. Some pertinent results of synthetic value are shown in Scheme 5. The addition of decalin diminished the alkylation reaction to give Ae reduction product 1-phenylpropane. 

Ransley has examined in detail the AlCb-catalyzed alkylation of benzene with a series of a,(o-di-chloroalkanes, and suggested possible mechanisms for the formation of the various phenylated products. With 2,4-dihalohexanes as the alkylating agents for benzene, Gelin et al. found that about 90% of the products consisted of 1,4-dimethyltetralin and compounds derived from it. The alkylation of 1,3-di-methylbenzene by 2,5-dichloro-2,5-dimethylhexane in the presence of AICI3 has been reported to give a moderate yield of the tetrahydronaphthalene derivatives, as in equation (7S). 

As pointed out earlier, cycloalkylation reactions can also result from the reaction of arenes with bifunctional alkylating agents or in cases where bifunctional intermediates are involved. An example of the former is shown in equation (114), where a chiral, lactone-substituted alkene cyclizes with the arene to produce a chiral tetrahydronaphthalene derivative. 

In the thermally induced [2+2]-eycloaddition of methylenecyclopropanes with ketenes only the C=C-double bond of the ketenes react to give spiro[3.2]hexanones in good yields 21S). The reaction proceeds stereospecificly with methylenecyclopropanes substituted at the double bond. With diphenylketene, tetrahydronaphthalene derivatives are also formed216>. Transition metal compounds do not catalyze these or other reactions between methylenecyclopropanes and ketenes. 

The rearrangement of the 15-membered silyl ketene acetals 12 indicates a high relative asymmetric induction with the preferred formation of 16 from the ( )-substrates through the chairlike and 17 from the (Z)-substrates through the boatlike transition state. The rearranged product 14 obtained from the 14-membered silyl ketene acetal 13 immediately undergoes cyclization to give the tetrahydronaphthalene derivative 15018. 

In contrast, tetrahydronaphthalene derivative 14 requires temperatures > 138 °C for rearrangement955. 

The intermolecular coupling of homoallyl alcohols with o-bromoacetophenone 127 (Scheme 3-33) or o-bromostyryl ketones 129 (Scheme 3-34) gave dihydro- 128 and tetrahydronaphthalene derivatives 130 in a sequence of Heck and aldol or Heck and Michael reactions [185]. After addition of the arylpalladium species formed initially... 

A good example of a high-yielding photoreaction of synthetic utility is provided by the photoenol of the benzaldehyde (1), which can be trapped in very good yield (81%) by methyl 2-ethylacrylate, acting as a dienophile, to give the tetrahydronaphthalene derivative (2) (Nicolaou and Gray, Chapter 1). Related, intramolecular reactions of photoenols have provided routes to polycyclic carbon frameworks, such as the conversion of (3) into (4) (Nicolau et al.. Chapter 1). 

Besides these alkylations of soft nucleophiles with cr-alkenylpalladium intermediates, 7T-allylpalladium complexes, formed by carbopalladation of an allene with an arylpalla-dium halide intermediate, are able to cyclize by attacking a dialkyl malonate moiety (Scheme 20)P° Instead of allenes, which give methyleneindane derivatives, cyclic and acyclic 1,4-dienes have been employed to yield tetrahydronaphthalene derivatives in good yieldsl ... 

The 1-aza-2-bora-1,2,3,4-tetrahydronaphthalene derivative 22 is formed on thermal treatment of [(CH3)3SiNR]2BF, probably via an amino-iminoborane intermediate, (CH3)3Si-[2,6-(CH3)2C6H3]N-B=NC6H3(CH3)2-2,6 mass spectrum and NMR data ( H, B, C, Si) are... 

Darzens et al. also used readily available malonic acid ester derivatives as substrates in reaction with sulfuric acid. " More recent studies and the NMR evidence demonstrated that for the cyclization of 2-methylallyl malonate 9 the use of anhydrous hydrogen fluoride is advantageous and leads to dimethyl tetrahydronaphthalene derivative 10. ... 

Yu and Luo et al. reported a catalytic enantioselective benzylic C(sp )-H functionalization of 207 via a [l,5]-hydride transfer/cyclization sequence with the chiral complex of copper(II) and side-armed bisoxazoline 209 as catalyst, which provided tetrahydronaphthalene derivatives 208 in moderate to high yield with up to 69 % ee (Scheme 79). 

---