Strain-Driven Direct Cross-Aldol and -Ketol Reactions of Four-Membered Heterocyclic Ketones
Owing to the ring strain and α-heteroatom effect, the four-membered heterocyclic ketones can undergo direct cross-aldol and -ketol reactions without the need for preformed enol or “enolate-like” intermediates. Besides the organocatalyzed cross-ketol addition onto their highly active carbonyl group, their ability to act as a nucleophilic donor has also been explored. As a result, a number of discrete aldol adducts were synthesized and the distinct reactivities were successfully combined into a double-aldol one-pot reaction.
Budapest is the largest city and also the capital of Hungary. It is the principal transportation, industrial, commercial, …
Championed first by the Ottomans, Budapest’s famed thermal baths include the sprawling, baroque Széchenyi Baths in City Park.