Macrocyclic oligoesters

In connection with studies on the ring-opening polymerization of cyclic acetals, we have undertaken investigations on the polymerization of bicyclic acetals, bicyclic oxalactone, and bicyclic oxalactam, which yield polysaccharide analogs, macrocyclic oligoesters, and a hydrophilic polyamide, respectively, some of which can be expected to be useful as novel speciality polymers. The monomers employed in the studies were prepared via synthetic routes presented in Scheme 1, starting from 3,4-dihydro-2H-pyran-2-carbaldehyde (acrolein dimer) I. 

Macrocyclic lattice hosts, 14 111 Macrocyclic mercuracarboranes, 4 216-217 Macrocyclic oligoesters, 25 125 Macrocyclic polymers, 14 252 Macrocyclic polythioethers, 23 707 Macrocylic ligands, 7 576 Macroemulsions, 10 113 16 433-434 Macrofouling organisms, in industrial water treatment, 26 149-150 Macrolide antibiotics, 15 271-320. See also Macrolides... 

FAB and MALDI-TOF techniques revealed that macrocyclic oligoesters were the main condensation products of catechol or 0,0 -Bistrimethylsilyl catechol (BTSC) with adipoyl chloride, sebaroyl chloride, and sebacoyl chloride, respectively. Macrocyclic polyesters were also obtained when the noncyclic l,3-bis(tributylstannoyl)butane was used as monomer. ... 

Figure 3.1 Transesterification as a reversible reaction to prepare macrocyclic oligoester DCLs.

SELECTIVE SYNTHESIS OF MACROCYCLIC OLIGOESTERS FROM A BICY-CLIC OXALACTONE AND CATION TRANSPORT THROUGH THEIR ORGANIC LIQUID MEMBRANES... 

Preparation of macrocyclic oligoesters has so far been achieved by two major approaches [1]. One is condensation of dibasic acid derivatives with glycols or dihalides, and the other is depolymerization of linear polyesters. However, the yield of macrocyclic oligoesters by these methods are generally unsatisfactory, and moreover, the product distribution is mostly controlled by intrinsic thermodynamic factors. In order to overcome these drawbacks, a new procedure using tin derivatives as covalent templates has been proposed recer tly for the synthesis of some macrocyclic tetra-esters [2]. 

Selective Synthesis of Macrocyclic Oligoesters from (i)-6,8-Dioxabicyclo[3.2.1]octan-7-one... 

The ion binding strength as evaluated from the Kg values in TABLE IV is comparable to that of beauvericin [12], an eighteen-membered depsipeptide belonging to enniatins, but it is much weaker than that of nonactin [13]. For both of the macrocyclic oligoesters, the Kg values decreased in the order, Cs" > Rb > K+ > Na+ > Li , and Ba " > Ca. ... 

In other words, an ion having a larger ion diameter and smaller heat of dehydration in the alkali and alkaline earth metal series is apt to be extracted favorably with the macrocyclic oligoesters from an aqueous phase into an organic phase. The selectivity sequence of alkali metal ions above belongs to the Eisenman s sequence I [14], and it is similar to that for beauvericin [15]. On the other hand, the selectivity sequence for nonactin is Rb+ >... 

Cs" > Na" [16], and also in this respect, the macrocyclic oligoesters differ from nonactin. 

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