3.7- Dimethyl-3-phenyl-7-octene

SYNS ACETIC ACID, PHENYL-, 3,7-DIMETHYL-6-OCTENYL ESTER BENZENEACETIC ACID, 3,7-DIMETHYL-6-OCTENYL ESTER (9CI) 3,7-DIMETHYL-6-OCTEN-l-YL PHENYLACETATE... 

The chiral 3,9-dimethyl-6-phenylundecane (III) may be taken as a suitable structural model for styrene copolymers. The former has two asymmetric carbon atoms of the same absolute configuration in 6 position with respect to the phenyl group and it is formally similar to a copolymer section where one unit derived from styrene is inserted between two monomeric units derived from the chiral 3-methyl substituted a-olefin, 3,7-dimethyl-1-octene [4]. 

A new parameter space for the synthesis of silsesquioxane precursors was defined by six different trichlorosilanes (R=cyclohexyl, cyclopentyl, phenyl, methyl, ethyl and tert-butyl) and three highly polar solvents [dimethyl sulfoxide (DMSO), water and formamide]. This parameter space was screened as a function of the activity in the epoxidation of 1-octene with tert-butyl hydroperoxide (TBHP) [26] displayed by the catalysts obtained after coordination of Ti(OBu)4 to the silsesquioxane structures. Fig. 9.4 shows the relative activities of the titanium silsesquioxanes together with those of the titanium silsesquioxanes obtained from silsesquioxanes synthesised in acetonitrile. The values are normalised to the activity of the complex obtained by reacting Ti(OBu)4 with the pure cyclopentyl silsesquioxane o7b3 [(c-C5H9)7Si7012Ti0C4H9]. 

The complexes HCo(CO)3L, where L is a variety of phospholenes, phospholes, and a phospholane, were compared under industrial conditions for the hydroformylation of 1-octene. It was found that 3,4-dimethyl-phospholenes and phospholes give comparably high yields of linear 1-nonanol and that both classes of ligands gave more efficient and more selective catalysts than the best phosphine, 9-phenyl-9-phosphabicyclononane. It was argued that the phospholes are strongly bound to cobalt, greatly increase the hyd-ridic character of the Co-H bond, and favor the formation of HCo (CO)2L (olefin) in preference to HCo (CO)3 (olefin) under the reaction conditions. 

Among the odorants listed in Table 6.33, l-octen-3-ol (no. 4), the character impact aroma compound of mushrooms [62], is also responsible for the characteristic mush-room-like note of camembert, which is intensified by l-octen-3-one (no. 5). Although the concentration of this ketone is much lower than that of the alcohol, it can be aroma-active in cheese because its odour threshold is 100 times lower than that of the alcohol [60], Methanethiol, methional, dimethylsulphide, dimethyl trisulphide and methylene-bis(methylsulphide) generate the sulphurous odour note, whereas phenyle-thyl acetate is responsible for the floral odour note [61 ]. 

The 1,2-dihydrophosphinine oxides are versatile intermediates [4,5] and are suitable to take part in Diels-Alder reaction with different dienophiles, like N-phenyl maleimide and dimethyl acetylenedicarboxylate (DMAD) [47]. These cycloadditions were also performed on MW irradiation in the absence of any solvent. Starting from the 1-phenyl-dihydrophosphinine oxide (23), the reactions were 25 times faster as compared to the thermal variations, and the valuable cycloadducts 2-phosphabicyclo[2.2.2]octene 24 and 2-phosphabicyclo[2.2.2]octadiene 25 were obtained in excellent yields with high purity (Scheme 8) [48]. 

When the steric bulk in the group R of the alkene R-GH=GH2 is increased, the preference for linear product increases without much loss of velocity, provided that no direct substitution at the vinyl group is involved. This was carried out both with triphenylphosphine and with o-Bu -phenyl phosphite, 5. The selectivity toward the linear aldehyde increases progressively with substitution, from 66% for 1-octene up to 100% for 3,3-dimethyl-1-butene. 

---