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Transition‐Metal‐Free Ring‐Opening Reaction of 2‐Halocyclobutanols through Ring Contraction
Author(s) -
Oeser Petr,
Edlová Tereza,
Čubiňák Marek,
Tobrman Tomáš
Publication year - 2021
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.202100837
Subject(s) - chemistry , ring (chemistry) , indene , reagent , reaction mechanism , grignard reaction , derivative (finance) , transition metal , polymer chemistry , stereochemistry , medicinal chemistry , combinatorial chemistry , organic chemistry , catalysis , financial economics , economics
The present work describes the preparation of halohydrins from 2‐halocyclobutanones by means of reactions with Grignard reagents at −78 °C. We discovered that the prepared cyclobutanols underwent a thermal ring‐opening reaction. Depending on the structure of the starting cyclobutanol, different products were formed. More specifically, 1‐substituted 2‐bromocyclobutan‐1‐ol was found to open to γ‐substituted butyrophenones. A novel 1,3‐dihydro‐2H‐inden‐2‐ylidene derivative was obtained for indene‐derived cyclobutanols. Based on the outcomes of the performed experiments, a mechanism for the ring‐opening of cyclobutanols can be proposed.