Decalol

As previously described, a mixture of and J -octalins can be prepared by the reduction of naphthalene or Tetralin. Another route to this mixture is the dehydration of a mixture of 2-decalol isomers. This latter route has certain advantages in that one can avoid the handling of lithium metal and low-boiling amines. Moreover, 2-decalol is available commercially or can be prepared by the hydrogenation of 2-naphthol (5). In either case a comparable mixture of octalins is obtained, which can be purified by selective hydroboration to give the pure J -octalin (Chapter 4, Section III). 

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Decalin. Decalin was chosen to study the reactivities and selectivities of and a-(5 disubstituted cyclohexane ring as well as the influence of the adjonction of a second saturated Cf, ring. The cis- and trans-isomers were photoxidized in the same conditions. The cis-isomer was found at least 10 times more reactive with a selectivity of 81% in mild oxidation products and 19% in CO2. The following relative selectivities for the main mild oxidation products (2-decalone, with small amounts of 1-decalone and 2-decalol (decahydro-2-naphtol) were found ... 

Hydrogenation of franr-2-decalone (23) with a fixed conformation gave trans,trans-2-decalol (the axial alcohol) in a high stereoselectivity of 98% both with rhodium catalyst in THF-HC1 and with platinum catalyst in AcOH-HBr. On the other hand, the hydrogenation stereochemistry of cis-2-decalone (24) is complicated by the two interconvertible conformations as shown in Scheme 5.9. A mixture of 66% cis,trans and 34% cis,cis isomers was obtained over rhodium in THF-HC1. Similarly, a mixture of 44% cis,trans and 56% cis,cis isomers was produced over platinum in AcOH-HBr.163... 

Naphthol was similarly hydrogenated to 2-decalols in 90% yield over 7 3 rhodium-platinum oxide in acetic acid (eq. 11.77).166... 

TIN, decalins TN, tetralin DL, 2-decalols 2-TO, 2-tetralone ac-2-TL, ac-2-tetralol ar-2-TL, ar-2-tetralol. The selectivities for ac-2-TL and ar-2-TL were obtained by application of the equation in Scheme 11.7. The selectivities for the other products were obtained by an extrapolation method. 

Newman et al. found that the hydrogenolysis of 1,2-epoxydecane over Raney Ni in ethanol at 150°C and 6.2 MPa H2 gave an approximately 9 1 mixture of 1- 2-decalol, while the ratio was reversed to 1 10-20 when the epoxide was hydrogenated with addition of a small amount of sodium hydroxide.18 In contrast, the course of the hydrogenolysis of styrene oxide was not affected by acid or alkali 2-phenylethanol was always formed preferentially. Mitsui et al. investigated the hydrogenation of 1,2-epoxydecane in detail with nickel wire, Raney Ni, palladium wire, and Pd-C as catalysts in ethanol at 150°C and 6 MPa H2.19 The results summarized in Table 13.1... 

Apparently aldehyde and ketone. dRatio of 1-decalol 2-decalol. 

By the same method, and with 0.33 g. of catalyst per gram of reactant, hydroquinone and resorcinol afforded 90% and 85 % of 1,4-cyclohexanediol and 1,3-cyclohcxancdiol, respectively, and 2-naphthol gave in 88% yield a mixture of 2-decalol geometrical... 

Exploitation of the complementary specificities of enzymes from different sources towards the same racemic substrate permits very precise control of the product stereochemistry. For example, any one of the three diastereomeric 2-decalols (94)-(96) can be obtained at will from ( )-tra/iJ-2-decalone (81 R = H) using the alcohol dehydrogenases HLADH, MJADH or CFADH, respectively (Scheme 40). The stereospecificities of these three enzymes are well documented and a simple active site model of predictive value is available for each. 55 Racemic bridged bicyclic ketones are similarly discriminated, either... 

Decalol, dehydration, 50, 92 Dewar benzene, 50,51 trans-1,8-Diacetoxybicyclo [4.2.0 ] octa-2,4-diene, 50,24 trans, [Pg.57]

Decahydro-P-naphthol CAS 825-51-4 EINECS/ELINCS 212-545-3 Synonyms Decahydro-2-naphthol cis-trans-Decahydro-p-naphthol trans-Decahydro-2-naphthol trans-Decahydro-p-naphthol Decahydro-2-naphthol, mixt. of isomers 2-Decalinol 2-Decalol 2-Hydroxydecalin Naphthalen-2-ol, decahydro- 2-Naphthalenol, decahydro-... 

Decalinol. See Decahydro-p-naphthol Decalin solvent. See Decahydronaphthalene 2-Decalol. See Decahydro-P-naphthol Decambrette Decambrette. See 9-Decenyl propionate... 

The four isomeric [l,l,4,4- H4]3-dimethylamino-trans-2-decalols have been synthesized in order to investigate their conformations. Where the amino-function is axial and the hydroxy equatorial, /h-2—h-3 = spectral measurements... 

Optical resolution of trans-1 -decalol, trans-2 -decalol has been carried out and conversions into trans-decalones of high optical purity have been effected. trans-syn-trans-Perhydroanthracen-2. -ol was also resolved and converted into the ketone. 

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