Hexahydronaphthalene

In a comparative study, Jacobson et al. have shown that for the cis-fused cyclohexadiene, l,2,3,4,4a,8a-hexahydronaphthalene, the dienophilic reactivity follows the order PTAD > cis-DEAZD > trans-DEAZD, while the order is reversed for their reactivity as enophiles.67 Other studies have produced similar conclusions.21,54 In general, azo compounds give more ene product than the corresponding C=C compounds. 

Cyclohexadiene, generated by the reaction of MeLi with the dibromide formed from cyclopentene and dibromocarbene, is so reactive as to add to styrene and 1,3-butadiene [19]. Hexahydronaphthalene 22 was formed by thermolysis of 21 and 21 via diradical 23 [20]. 

Intramolecular [4 + 2]-cycloadditions of vinylallenes have been utilized in the synthesis of complex molecules including natural products such as compactin. Heating the vinylallene 208 at 140 °C gave hexahydronaphthalene 209. The crude mixture was immediately reduced with LiB(sBu)3H because of the instability of /3,y-unsatu-rated ketones [175]. 

Termites are a serious problem in several known limited areas and are on the increase. White refined arsenic has been used in Cuba with some success but has not resulted in control. Treatment of 13,000 infested acres required 1800 pounds of arsenic in 1953. Dieldrin and similar compounds appear more promising at present. Aldrin (hexachloro-diendomethano-hexahydronaphthalene) has been used at the rate of 2 pounds per acre on 750 acres in the Dominican Republic with good results. Termites do not seem to be a general hazard at this time. 

Hexadiene-3-ol, hydrogenation, 30 361 Hexadiene, reaction with HCN, 33 19-20 Hexafluoropropene oxide oligomers, 42 497 Hexahydronaphthalenes, intermediates of naphthalene hydrogenation, 18 32, 33... 

ESR spectra for, 22 294, 301 as high-energy fuels, 18 2-4 hydrogenation course of, 18 6-8 equilibria, 18 7, 8 kinetic processes, 18 6, 7 experimental procedures, 18 19, 20 apparatus and methods, 18 20 materials, 18 20 mechanism of, 18 21-45 formation of isomeric decahydro-naphthalenes, 18 23-30 deuterogena-tion of - -octalin, 18 29 routes to trans isomers, 18 26-30 selectivity to trons-decalin, 18 24, 25 olefin intermediates, 18 30-45 dihydro-and hexahydronaphthalenes, 18 32, 33 analysis of products, 18 33 oc-tahydronaphthalenes, 18 34-45 analysis of products, 18 34 deu-... 

Reduction of nonconjugated aromatic ketones gave at metal cathodes (e.g., tin, copper, silver, palladium, zinc) the cis isomers (ds-H/OH) of cycKzed products in high diastereoselectivity. The electroreduction of 5-phenylpentan-2-one led to 70% of an exclusively ds-hexahydronaphthalene... 

Chemical Class Substituted hexahydronaphthalene I Clinical Pharmacology ... 

Kozikowski and Li (268) also made use of this protocol for the construction of the hexahydronaphthalene portion of the hypocholesteremic agent compactin (256) (see Section 6.4.2.2). The oxime derived by from alcohol 253 (via y-lactone 252) was heated with aqueous sodium hypochlorite in the presence of triethylamine to give the tricyclic isoxazoline adduct 254 (Scheme 6.96). Reductive hydrolysis and dehydration afforded enone 255, which in several further steps led to compactin (256) (268). 

Thieno[2,3-. ]pyridine derivatives, 155, can be successfully used as replacements for the hexahydronaphthalene ring found in naturally occurring 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors <2001BML1285>. These compounds also display significant inhibition of cholesterol biosynthesis in vivo. 

The hexahydronaphthalene ring system of compactin has been constructed by a nitrile oxide cycliza-tion strategy (Scheme 24).42 Thus, cyclization of either (83) or (84) via nitrile oxide intermediates led to... 

Farnum, Mehta, and co-workers have shown that longifolene 218 and isolongifolene 219 in HSO3F media give a mixture of cyclohexenyl cations at different temperatures. Quenching these cations provides some unusual sesquiterpene like Cis-hexahydronaphthalenes 220-225 (Scheme 5.82). 

Ene reactions with bicyclic systems are not limited to simple alkenes 1,3-dienes with suitable stereogenic centers can also react in an ene fashion. This has been shown by Sasson and Labovitz77 in their work on the photooxygenation of hexahydronaphthalenes. 

Conjugate addition of dimethylcopperlithium to 3.4,5,6,7,8-hexahydronaphthalene-l(2H)-one-7-carboxylic acid (1) affords a mixture of three stereoisomcric 4o-methyl-3,4,4a,5,6,7,8,8a-octahydronaphthalenc-l(2H)-one-7-carboxylic acids, (2), (3), and (4),... 

Rather rare examples of the oxidation of tertiary alcohols are the degradation of 3-ethyl-3-pentanol to 3-pentanone and iodoethane in respective yields of 90 and 84% by acetyl hypoiodite in acetic acid and chlorobenzene under irradiation for 1 h at 20-25 °C [780 and the conversion of trflnj-9,10-dihydroxy-l,4,5,8,9,10-hexahydronaphthalene into 3,8-cyclodecadiene-l,6-dione and its tetramethylacetal by lead tetraacetate (equation 274) [447. ... 

---