Octyl synthesis

The 1,6-difunctional hydroxyketone given below contains an octyl chain at the keto group and two chiral centers at C-2 and C-3 (G. Magnusson, 1977). In the first step of the antithesis of this molecule it is best to disconnect the octyl chain and to transform the chiral residue into a cyclic synthon simultaneously. Since we know that ketones can be produced from add derivatives by alkylation (see p. 45ff,), an obvious precursor would be a seven-membered lactone ring, which is opened in synthesis by octyl anion at low temperature. The lactone in turn can be transformed into cis-2,3-dimethyicyclohexanone, which is available by FGI from (2,3-cis)-2,3-dimethylcyclohexanol. The latter can be separated from the commercial ds-trans mixture, e.g. by distillation or chromatography. 

Of course, a primary concern for any physical property measurement, including gas solubility, is the purity of the sample. Since impurities in ILs have been shown to affect pure component properties such as viscosity [10], one would anticipate that impurities might affect gas solubilities as well, at least to some extent. Since ILs are hygroscopic, a common impurity is water. There might also be residual impurities, such as chloride, present from the synthesis procedure. Surprisingly though, we found that even as much as 1400 ppm residual chloride in l-n-octyl-3-methylimi-dazolium hexafluorophosphate and tetrafluoroborate ([OMIM][PFg] and [OMIM] [BF4]) did not appear to have any detectable effect on water vapor solubility [1]. 

This modification was used in the synthesis of (-)-avenaciolide. The key step is the trans-diastereoselective Michael addition of the lithium enolate of tert-butyl 2-(phenylse-leno)propionate (THF, — 78 CC) to (R)-5-octyl-2(5//)-furanone and subsequent trans-diastereoselective iodonation318. u e... 

Under comparable conditions, the reaction rates of the octyl decanoate synthesis by chromobacterium viscosum lipase in AOT-based microemulsions or immobihzed in AOT-based organogels were similar [286,287],... 

In some cases shape-control has also been achieved tetra( -octyl)ammonium glycolate transforms Pd(N03)2 predominantly into trigonal Pd particles [186]. Recent work has confirmed that the colloidal protective agents not only prevent particle agglomeration but even provide control of the crystal growth during particle synthesis (see e.g., Ref. [187-191]). The drawbacks of this route are the restriction to noble metal salts and the limited industrial availability of A-(octyl)j RC02. 

A. Basso, A. Ducret, L. Gardossi, and R. Lottie, Synthesis of octyl glucopyrano-side by almond /i-ghicosidase adsorbed onto Celite R-640 , Tetrahedron Lett., 43 (2002) 2005-2008. 

Tab. 5.2 Synthesis ofn-octyl acetate under MW + PTC conditions (Synthewave, 5 min, 160°C).

The synthesis of octylthiocyanate by reaction of n-octyl bromide with KSCN, and its subsequent isomerization to isothiocyanate, have been realized by use of TBAB under the action of MW irradiation. The effect of inorganic solid supports was studied (Si02, K10, graphite, NaCl) (Eq. 64). 

The oxazoline methodology can be applied in the total synthesis of natural products. For example, in the course of the total synthesis of European pine-saw fly pheromone 47, the key intermediate, chiral a-methyl carboxylic acid 46, was prepared via the reaction of a-lithioethyloxazoline with n-octyl iodide. The product 2-methyl decanoic acid 46 was obtained, after hydrolysis, in 72% ee (Scheme 2-26).51... 

Octyl thiocyanate synthesis/isomerization, microwaves in, 16 566 Octyltriethoxysilane, as silylating agent, 22 697... 

A typical (industrially applied) example for the synthesis of monoalkylglyceryl ethers [39, 40] consists of the transition metal-catalyzed conversion of glycerol and butadiene (telomerization) to yield glyceryl unsaturated octyl and dioctyl ethers (Scheme 11.5). 

C. Marutoiu, M. Filip, C. Tigae, V. Coman, R. Grecu and G. Marcu, Synthesis and characterization of alumina R chemically modified with w-octyl for use as a stationary phase in TLC. J. Planar Chromatogr.-Mod. TLC 16 (2003) 186-191. 

A procedure, which has been used successfully for the synthesis of dialkyl thioethers from thioacetamide has been extended to the preparation of a range of 5-alkyl thiocarboxylic esters [35] (Table 4.20). The intermediate 5-acyl ethaniminium salt (Scheme 4.14) is not stable and is converted directly into the 5-alkyl thioester. The choice of catalyst affects the yield of the thioesters. Thus, 5-n-octyl thiobenzoate... 

O Gara et al. [44] from Waters Corporation reported the preparation of an embedded octyl carbamate phase (12% C) using a single-step synthesis in 1995, having the structure... 

Scheme 1 Synthesis of cross-linked PPEs by the palladium-catalyzed cross-coupling reaction of 2,5-diiodo-4-[(2-ethylhexyl)oxy]methoxybenzene, l,4-diethynyl-2,5-bis(octyloxy)ben-zene, and the trifunctional cross-linker 1,2,4-tribromobenzene. R =2-ethylhexyl, R =n-octyl...

Fig. 4. Synthesis of F-octyl bromide by bromination of F-octyl iodide produced by telo-merization of tetrafiuoroethyiene, the monomer of Teflon . F-octyl iodide is the precursor of numerous fiuorosurfactants.

The detailed synthesis of the IL s used here was described earlier (6). Two samples were prepared having R = butyl but the Al/cation ratio was 3/2 and 2 mol/mol. One sample each was prepared having R = ethyl, hexyl, octyl, and dodecyl for which the Al/cation = 2 mol/mol. 

---