Diethylene glycol ditosylate

Diethylene glycol ditosylate [7460-82-4] recrystn from Me2CO and dried in a vacuum. 

When K.yba, Cram and coworkers attempted the synthesis of dibinaphthyl-22-crown-6 from binaphthol and diethylene glycol ditosylate. the reagent ratio was as described either by V or X (Eqs. 3.1 or 3.3). The intent was to make the 22-membered ring. Some of the 11-membered ring was isolated as well (Eq. 3.5). None was apparently observed for the benzo case because the nine-membered ring is less favorable. In short, it is not the intent of the synthesis but the reaction dynamics which determine the product. 

Stoddart and his coworkers have reported syntheses of the trans-syn-trans and the trans-anti-trans isomers of dicyclohexano-18-crown-6 The synthesis of these two compounds from trans-l,2-cyclohexanediol was accomplished in two stages. First, the diols were temporarily linked on one side by formation of the formal, and this was treated with diethylene glycol ditosylate and sodium hydride to form the hemi-crown formal. Removal of the formal protecting group, followed by a second cychzation completed the synthesis. The synthesis of the trans-anti-trans compound is illustrated below m Eq (3 12) and the structures of the five possible stereoisomers are shown as structures 1—5. 

Boujlel and Simonet used an electrochemical method to prepare a group of similar compounds, including compound ]5, shown in Eq. (3.41). In a typical case, benzil was reduced in DMF solution at the dropping mercury electrode in the presence of tetrabutylammonium iodide, used in this case as a supporting electrolyte rather than phase transfer catalyst. In the presence of diethylene glycol ditosylate, compound 15 (mp 77— 78°) was isolated in 10% yield. Using the same approach, acenaphthenedione was reduc-tively cyclized with triethylene glycol ditosylate to afford the product (mp 84—85°, 42% yield) shown in Eq. (3.42). 

In Cram s first synthesis of a chiral bis-binaphthyl system, optically pure binaph-thol and diethylene glycol ditosylate were heated at reflux in tetrahydrofuran solution for 15 h with potassium f-butoxide, two products were obtained. The 1 + 1 product (mp 230—231°) was isolated in 5% and the 2 + 2 product (mp 123—126°) was obtained in 31% yield. The reaction is shown in Eq. (3.51). 

Coxon and Stoddart have directed their attention to the formation of penta-erythritol-derived cryptands. With these molecules, the strategy was to block one pair of hydroxyl groups as an acetal and form a crown from the remaining diol. In the first of the two reports cited above, this was accomplished by treating the 0-benzylidine derivative of pentaerythritol with base and diethylene glycol ditosylate. The crown was then treated with a mixture of UAIH4 and BF3 which gives partial reduction of the acetal as shown in (8.9), above. The monoprotected diol could now be treated in a fashion similar to that previously described and the benzyloxy cryptand (77) would result. The scheme is illustrated below as Eq. (8.10). 

A base-promoted (2 -t- 2) cyclization between l,2 5,6-di-0-isopropylidene-D-mannitol (Figure Ab) and diethylene glycol ditosylate had previously been applied (88, 106, 107) successfully to the preparation of the chiral 18-crown-6 derivative dd-27 (p. 228), whence dd-28 to dd-30 can be obtained. However,... 

Diethylene glycol ditosylate [7460-82-4] M 414.5, m 86-87 , 87-88 , 88-89 . Purified by recrystn from Me2CO and dried in a vacuum. 

Merz48 showed that reaction of benzoin with diethylene glycol ditosylate, in the presence of TBAB and of aqueous sodium hydroxide, yields 20% of crown ether 12. This result, however, does not seem to be in agreement with the usual template effect, achieved by complexation around a Na+ or K + ion, as in the usual final step of crown ether syntheses.30... 

Ditosyl derivative of 1,4,7-oxadiazonane was synthesized from /V,/V -ditosyl diaminoethane and diethylene glycol ditosylate (see Scheme 42, Section 14.10.7.5) <2004T5799> or with l-chloro-2-(2-chloroethoxy)ethane <1998JRM1448>. Similarly, Richman-Atkins cyclization of ditosyl-substituted ethylenediamine with ditosylate of iV,iV-bis(2-hydroxyethyl)-4-methylbenzenesulfonamide gave the functionalized triazonanes <2003OBC2357>. 

The yield of the tetraaza-18-crown-6 product was 40% with potassium carbonate but only 10% when sodium carbonate was used. The amount of 9-crown-3 by-product was greater when sodium carbonate was used. The same reaction using diethylene glycol ditosylate instead of 2-chloroethyl ether with cesium carbonate as the base was reported recently, but with only a 20% yield (Craig et al., 1989). 

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