Cyclohexane, 1,3,5-trimethyl

The optimum parameters for furfural-benzene are chosen in the region of the overlapping 39% confidence ellipses. The ternary tie-line data were then refit with the optimum furfural-benzene parameters final values of binary parameters were thus obtained for benzene-cyclohexane and for benzene-2,2,4-trimethyl-pentane. Table 4 gives all optimum binary parameters for this quarternary system. 

Figure 4-23. Calculated and experimental selectivities and distribution coefficients for the type-I ternaries in the 2,2,4-trimethyl pentane-cyclohexane-furfural-benzene system.

Properties Neopentyl glycol (1) 2,2,4-Trimethyl-l,3-pent anediol (7) 1,4-Cyclohexane-dimetha nof (8) Hydroxypivalyl hydroxypivalate (9)... 

A decisive breakthrough to a T range above 230°C was achieved with a polycarbonate based on spitobisiudan (SBI-PC, (8)) (203) or 3,3,5-trimethyl cyclohexane (TMC-PC, (7) whereia the cyclohexane ring bears three methyl groups) (204). 

The stmcture of vitamin A [11103-57-4] and some of the important derivatives are shown in Figure 1. The parent stmcture is aH-Zra/ j -retinol [68-26-8] and its lUPAC name is (all-E)-3,7-dimethyl-9-(2,6,6-trimethyl-l-cyclohexen-l-yl)-2,4,6,8-nonatetraen-l-ol (1). The numbering system for vitamin A derivatives parallels the system used for the carotenoids. In older Hterature, vitamin A compounds are named as derivatives of trimethyl cyclohexene and the side chain is named as a substituent. For retinoic acid derivatives, the carboxyl group is denoted as C-1 and the trimethyl cyclohexane ring as a substituent on C-9. The stmctures of vitamin A and -carotene were elucidated by Karrer in 1930 and several derivatives of the vitamin were prepared by this group (5,6). In 1935, Wald isolated a substance found in the visual pigments of the eye and was able to show that this material was identical with Karrer s retinaldehyde [116-31-4] (5) (7). 

Whereas reduction of dimethyl 1,2,7-trimethyl-l T/-azepine-3,6-dicarboxylate (5) with platinum and hydrogen in cyclohexane yields the hexahydroazepine 6, hydrogenation in methanol solution results in loss of methylamine and formation of dimethyl 2,3-dimethylbenzene-1,4-dicar-boxylate (52% mp 66-67 C).239... 

Tab. 25 Hydrid-Reduktion des gehinderten 5-Oxo-1,1, 3-trimethyl-cyclohexans unter asymmetrischer Induktion zu cis- und trans-5-Hydroxy-1, 1,3-trimethyl-cyclohexan...

A patent procedure for formation of compounds 19 from simple tartaric acid derivatives has appeared <06USP047129> and various new routes to chiral dioxolanones include synthesis of dioxolan-2-ones either by transition metal-mediated asymmetric synthesis <06T1864> or enzyme-mediated kinetic resolution <06H(68)1329> and a new synthesis of the chiral dioxolan-4-ones 21 from lactic or mandelic acid involving initial formation of intermediates 20 with trimethyl orthoformate in cyclohexane followed by reaction with pivalaldehyde <06S3915>. 

Trimethyl- 1-butene r/.v.r/.v-1.3.5-Trim ethyl cyclohexane Trimethylene oxide... 

Trimethylsilyloxy)methylene]cyclohexane Silane, (cyclohexylidene-, methoxy)trimethyl- (9) (53282-55-6)... 

Die Reaktion von 1,2-Epoxy-cyclohexan mit Cyan-trimethyl-silan in Gegenwart von katalytischen Mengen Zinkchlorid fiihrt zur Bildung von 2-Isocyan-1-trimethylsilyloxy-cyclohexan, das sich mit Ammoniumchlorid in Methanol/Wasser (9 1) zu 2-Isocyan-l-hydroxy-cyclohexanol desilylieren laflt katalytische Hydrierung ergibt dann 2-Methylami-no-l-hydroxy-cyclohexan1 (vgl. S. 1188) ... 

A mixture consisting of the step 2 product (37 g) and 800 ml trimethyl phosphate were charged into a flask and treated with iodine (10.6 g) and the dropwise addition of bromine (19 g) dissolved in 70 ml trimethyl phosphate. After stirring for 4 hours additional bromine (9.5 g) dissolved in 35 ml of trimethyl phosphate was added and the mixture stirred overnight. The reaction liquid was then poured into water, extracted with chloroform, and washed with aqueous solutions of sodium thiosulfate and brine. The solution was then dried, concentrated, the residue purified by silica gel chromatography using cyclohexane/toluene, 20 1, respectively, and... 

Fig. 1. Two illustrative graphs 2,3,4-trimethyl-pentane (Gi) and sec-butyl-cyclohexane (G2)...

H-NMR studies on 2,6-dimethylmorpholine314 and N-substituted 2,6-dimethylmorpholines315 are consistent with the single diequatorial conformation 391 for the cis isomers and with the equilibrium 392 393 for the trans isomers. The 13C-NMR spectrum of the monomethyl-, 2,3-, 2,5-, 2-6-, 3-5-dimethyl-, 2,3,4-, 2,3,6-trimethyl-, and 2,3,5,6-tetramethylmorpholines are largely consonant with expectations based on conformational principles derived from cyclohexane conformational analysis.316 The all-cis 2,3,5,6-isomer, which did not prove amenable to analysis by H-NMR spectro-... 

Solvent cyclohexane the positions of the peak maxima (nm) are given, with log10 s values in parentheses mainly from Mason (59JCS1240,59JCS1247).b Trimethyl derivative. 

Epoxide formation is nearly suppressed when massively subeti-tuted olefine, such as 2,2,4-trimethyl-3-hexene among others, ate subjected to the chromic oxide-acetic anhydride reagent,42 Cyclo-hexene yields primarily 2-cyclohexenone and cyclohexane- 1,2-dione777 although some cyclohexane oxide appears to bo formed also (Eq, 111). 

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