Tri-o-thymotide

Optically active thiiranes have been obtained by resolution of racemic mixtures by chiral tri-o-thymotide. The dextrorotatory thymotide prefers the (5,5)-enantiomer of 2,3-dimethylthiirane which forms a 2 1 host guest complex. A 30% enantiomeric excess of (5,5)-(—)-2,3-dimethylthiirane is obtained (80JA1157). 

Multimolecular helical inclusion networks formed by rigid alicyciic diols, urea, deoxycholic acid, and tri-o-thymotide are described and contrasted, followed by discussion of DNA intercalates, amylose compounds, and other inclusion systems formed by helical polymers. 

Unsolvated tri-o-thymotide (TOT) (20) crystallises in the orthorhombic space group Pna21 101 102) but forms inclusion compounds with an extremely wide range of organic materials (> 100) in different arrangements 103). 

Classifying particles, in filtration, 11 326 Class I hybrids, 13 536, 543, 544 Class II hybrids, 13 536, 543 Clastogenesis, 25 206 Clathrate hydrates, 14 170—171 Clathrate receptor chemistry, 16 797 Clathrates, 12 374 14 159, 170-182 formation of, 10 633-635 26 869 Hofmann- and Werner-type, 14 171-172 phenol-type, 14 180 tri-o-thymotide, 14 179 Claus catalysts... 

The gas-solid addition of HCl or HBr to simple alkylated oxiranes requires their inclusion. (-)-(M)-Tri-o-thymotide (150) (P3i21) selectively enclathrates the oxiranes 151 or 153 with 13-14% ee for (-i-)-(3P)-151 or 51-5Wo ee for (-1-)-(2P,3P)-153. Isolated molecules in the chiral cages of 150 react stereoselectively with HCl or HBr gas to give the products 152 and 154, respectively, in almost stereopure form according to the optical rotations after quantitative reaction under the influence of the chiral environment [78] (Scheme 17). The host lattice is preserved during the reactions, but destroyed during liberation of the product molecules. 

The history of inclusion compounds (1,2) dates back to 1823 when Michael Faraday reported the preparation of the clathrate hydrate of chlorine. Other early observations include the preparation of graphite intercalates in 1841, the 3-hydroquinone H2S clathrate in 1849, the choleic acids in 1885, the cyclodextrin inclusion compounds in 1891, and the Hofmann s clathrate in 1897. Later milestones of the development of inclusion compounds refer to the tri-o-thymotide benzene inclusion compound in 1914, phenol clathrates in 1935, and urea adducts in 1940. 

Fig. 15. Macrocyclic and oligocydic lattice hosts perhydrotriphenylene (32) a cyclotriphosphazene (33) cyclotriveratrylene (34) tri-o-thymotide (35).

There are numerous other examples of stereochemical correspondence in propeller molecules. The propellane 19> 1e has only one energetically reasonable isomerization mechanism available a twisting motion about the C3 axis which corresponds to the three-ring flip as well as to the trigonal twist rearrangement (Fig. 5). Similarly, only one isomerization mechanism (stereochemically correspondent in the permutational sense to the zero-ring flip) is energetically reasonable for tri-o-thymotide (Id). 8,20)... 

Common hosts such as urea or p-f-butylcalix[4]arene can exist as various crystal phases, some if which do not contain cavities. The crystal form of the pure host without cavities is called the a-phase. The 30 (apohost) phase contains unfilled cavities while the p -phases have the same host structure but contain different guests. Such structures are sometimes referred to as pseudopoly morphs. Further pure phases (y-phase) or clathrates (y1. phases) may also exist in some cases, as in tri-o-thymotide. Apohosts are usually relatively unstable but allow the inclusion of interesting guests such as gases. 

Bonner, W. A., Enantioselective autocatalysis. V. The spontaneous resolution of tri-o-thymotide. Orig. Life Evol. Biosph. 1999, 29, 317-328. 

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