ISSN:
1022-1352
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
2,2-Dibutyl-2-stanna-1,3-dioxacycloalkanes were prepared from dibutyltin oxide and 1,2-ethanediol, 1,3-propanediol or 1,4-butanediol. These tin heterocycles reacted stoichiometrically with double molar amounts of γ-thiobutyrolactone by a stepwise insertion. In contrast to γ-thiobutyrolactone an excess of γ-thiocaprolactone resulted in additional insertion steps, i.e., polymerization of the thiolactone. Analogous insertion reactions were performed with a spirocyclic stannoxane derived from pentaerythritol. With ε-caprolactone macrocyclic polymerization took place without stoichiometric intermediates. When the 2,2-dibutylstanna-dioxepane was reacted with an equimolar amount of 1,3-dithian-2-one, the insertion step was immediately followed by a ring contraction reaction yielding 2-stanna-1,3-dithiane and trimethylene carbonate which polymerized immediately. The application of this reaction sequence to macrocyclic stanna poly(ε-caprolactone) yielded tin-free macrocycles along with 2,2-dibutyl-2-stanna-1,3-dithiane. This reaction sequence allows the synthesis of nontoxic, biodegradable macrocyclic polyesters.
Additional Material:
8 Ill.
Type of Medium:
Electronic Resource
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