ISSN:
0018-019X
Schlagwort(e):
Chemistry
;
Organic Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
Transamidation Reactions with Cyclic Amino-amidesLactames which are substituted at the nitrogen atom by a 3-aminopropyl residue are transformed under base catalysis to cyclic amino-amides enlarged by 4 ring atoms. The formed ring must be at minimum 12-membered. Scheme 2 illustrates this result: the 8-membered 7 is transamidated in 96% yield to the 12-membered ring 8 (in the presence of potassium 3-aminopropylamid in 1, 3-propanediamine), the 9-membered 10 to the 13-membered ring 11 (97%) and the 11-membered 14 to the 15-membered ring 15. Furthermore, the 13-membered ring 27 (Scheme 5) is transformed to the 17-membered 28. In the case of the 15-membered lactame 15 it is demonstrated that 14 is not formed back under the conditions of the transamidation.Large ring lactames which are substituted at the nitrogen atom by a 3-(alkylamino) propyl group lead under base catalysis to an equilibrium mixture, e.g. the 17-membered 26 is in equilibrium with the 21-membered 29. This result is similar to the behavior of the corresponding open-chain amino-amides [2].Because of transannular interactions, the 11-membered ring 2 is not stable: transamidation of the 7-membered 1 (Scheme 1) doesn't give the expected 2, but its water elimination product 3 in small yield. The N-tosyl derivative of 2, namely 20, is synthesized by an independent route (Scheme 3). Detosylation of 20 yields the 7-membered 1 instead of 2. Concerning the mechanism of this interesting reaction see Scheme 4.
Zusätzliches Material:
1 Tab.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/hlca.19780610315
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