1,1,6-trimethyl-1,2-dihydronaphthalene

Trimethyl-1,2-dihydronaphthalene Petroleum-like, kerosene-like 1-59 [5] 20 [5]... 

Treatment of -lonone (13) in Water. Traditional methods for the dehydration of a- and p-ionones to give ionene (14) have involved catalysis by hydriodic acid along with small amounts of phosphorus, or distillative heating in the presence of 0.5% iodine (18). This latter procedure is now known to co-produce about 10% 1,1,6-trimethyl-1,2-dihydronaphthalene (19). However, we have found that the cyclization could be effected by merely heating p-ionone in water at 250 °C for twenty minutes in the MBR. The microwave-assisted reaction was not optimized, and proceeded with only moderate conversion. Unlike in the literature method (18), however, the work-up did not require exhaustive washing procedures. 

Norisoprenoids, responsible for the typical aroma of some grape varieties, could originate from direct degradation of carotenoid molecules such as 3-carotene, lutein, neoxanthin, and violaxanthin. Some degradation carotenoid products have an important sensorial impact on wine, such as P-damascenone, P-ionone, 1,1,6-trimethyl-1,2-dihydronaphthalene (TDN), and vitispirane. These aromatic molecules have very low olfactory perception thresholds [40]. 

Oxidation of (6-trans-2 -trans)-6-(but-2 -enyliden)-1,5,5-trimethylcyclohex-l-ene to 1,1,6-trimethyl-1,2-dihydronaphthalene ... 

DOD, 2,6-dimethyl-l,7-octadiene-3,6-diol TDN, l,l,6-trimethyl-l,2-dihydronaphthalene. a Adapted from Camara (2004). 

Trimethyl-2-thioxo-1,2-dihydronaphthalene adds to electron-rich alkenes such as 2,3-dihydrofuran, ethyl vinyl ether, vinyl... 

Versini, G., Carlin, S., Dalla Serra, A., Nicolini, G. and Rapp, A. (2002) Formation of l,l,6-trimethyl-l,2-dihydronaphthalene and other norisoprenoids in wine. Considerations on the kinetics, in Carotenoid-derived Aroma Compounds, ACS Symp. Series 802, Am. Chem. Soc., Washington DC. 

The total neutral essential oil from M. oleifera leaves is composed of 44 constituents and include toluene, 5-ter/-butyl-l,3-cyclopentadiene, benzaldehyde, 5-methyl-2-furaldehyde, benzeneacetaldehyde, linaloloxide, 2-ethyl-3,6-dimethylpyrazine, undecane, a-isophorone, benzylnitrile, 2,6,6-trimethyl-2-cyclohexane-l, 4-dione, 2,2,4-trimethyl-pentadiol, 2,3 -epoxycarane, p-menth-1 -en-8-ol, 2,6,6-trimethylcyclohexa-1,3 -dienecarbaldehyde, indole, tridecane, a-ionone, l,l,6-trimethyl-l,2-dihydronaphthalene, a-ionene, (1-damascenone, 3-ionone, ledene oxide, 2-ter/-butyl-l,4-dimethoxybenzene, ( )-6,10-dimethylundeca-5,9-dien-2-one, 4,6-dimethyl-dodecane, 3,3,5,6-... 

Humph H.U., Winterhalter, E, and Schreier, P. (1991). 3,4-Dihydroxy-7,8-dihydro-P-ionone P-D-glucopyranoside natural precursor of 2,2,6,8-tetramethyl-7,ll-dioxatricyclo[6.2.1.01,6]undec-4-ene (Riesling acetal) and l,l,6-trimethyl-l,2-dihydronaphthalene in Red currant (Ribes Rubrurn L) leaves,./. Agric. Food. Chem., 39,1833-1835. 

Winterhalter, P. (1991). l,l,6-Trimethyl-l,2-dihydronaphthalene (TDN) formation in wine. 1. Studies on the hydrolysis of 2,6,10,10-tetramethyl-l-oxaspiro[4.5]dec-6-ene-2,8-diol rationalizing the origin of TDN and related Co norisoprenoids in Riesling wine,/. Agric. Food. Chem., 39,1825-1829. 

Figure 4.2. Principal norisoprenoid compounds in grape and wine. (29) TDN (1,1,6-trimethyl-l,2-dihydronaphthalene) (30) P-damascone (31) P-damascenone (32) vom-ifoliol (33) dihydrovomifoliol (34) 3-hydroxy-P-damascone (35) 3-oxo-a-ionol (36) 3-hydroxy-7,8-dihydro-P-ionol (37) oc-ionol (38) P-ionol (39) a-ionone (40) P-ionone (41) actinidols (42) vitispiranes (spiro [4.5]-2,10,10-trimethyl-6-methylene-l-oxa-7-decene) (43) Riesling acetal (2,2,6-tetramethyl-7,ll-dioxatricyclo[6.2.1.01,6] undec-4-ene).

Simpson, R.F. (1978). l,l,6-trimethyl-l,2-dihydronaphthalene an imp>ortant contributor to the bottle aged bouquet of wine. Chemistry Industry 1,37... 

The thallium(III)-mediated oxidative rearrangement of 1,2-dihydronaphthalenes has been explored intensively aiming the synthesis of indanes. The substrates on this transformation can be easily prepared from commercially available tetralones. The typical protocol is the use of TTN in MeOH or in trimethyl orthoformate (TMOF), which gives ring contraction products in excellent yield and diastereoselectivity. ° However, acetonitrile is the solvent of choice for some substrates bearing an alkyl group at the double. This rearrangement was used as the key step in the racemic and asymmetric syntheses of mutisianthol 48, which is a sesquiterpene with moderate antitumor activity (Scheme 18.12). 

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