The Formation of trans-Fused Macrocycles from N3,N3′-Polymethylenebis(hydantoins) by Ring-Closing Metathesis

✍ Scribed by Diederica D. Claeys; Christian V. Stevens; Nicolai Dieltiens

• Book ID: 102178112
• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: English
• Weight: 234 KB
• Volume: 2008
• Category: Article
• ISSN: 1434-193X
• DOI: 10.1002/ejoc.200700836

✦ Synopsis

Abstract

A straightforward ring transformation giving polymethylenebis(hydantoins) was extended, as these are HMBA analogues. Firstly, ethyl or allyl pyroglutamate was carbamoylated with a diisocyanate. Upon treatment with KO__t__Bu in allyl alcohol the bis(carbamoyllactam) rearranged to give the hydantoin, which was followed by the ring‐opening of the pyrrolidinone with formation of the allyl ester. These compounds were subsequently ring‐closed in the presence of second‐generation Grubbs' catalyst to form macrocycles containing the ester functionality in the ring. It was established by HSQC experiments with inverse detection that only the E isomers were formed in the cases of the 24‐ and 26‐membered heterocycles.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)