Synthesis of cyclodec-3-en-1-ols by acid-catalyzed two-carbon ring expansion

1973 ◽  
Vol 38 (9) ◽  
pp. 1758-1759 ◽  
Author(s):  
Richard W. Thies ◽  
James E. Billigmeier
Keyword(s):  
Ring Expansion ◽  
Carbon Ring ◽  
Acid Catalyzed

The formation of cycloheptenone and cycloheptadienones from bicyclo[3.2.0]heptanone derivatives. An acid-catalyzed, two carbon ring expansion reaction

1976 ◽  
Vol 54 (1) ◽  
pp. 12-18 ◽  
Author(s):  
Kenneth E. Hine ◽  
Ronald F. Childs
Keyword(s):  
Ring Expansion ◽  
Membered Ring ◽  
Acid Solutions ◽  
Ring Expansions ◽  
Carbon Ring ◽  
Ether Mixture ◽  
Synthetic Utility ◽  
Acid Catalyzed ◽  
Ring Expansion Reaction ◽  
Strong Acids

In strong acids, such as FSO3H and 96% H2SO4, bicyclo[3.2.0]heptan-6-one and bicyclo[3.2.0]hept-2-en-7-one undergo a clean isomerization to form protonated cyclohept-2-enone and cyclohepta-2,4-dienone, respectively. Substituted derivatives undergo comparable ring expansions when dissolved in these strong acids. The seven-membered ring ketones can be recovered on quenching the acid solutions with a NaHCO3–ether mixture. In contrast, bicyclo[3.2.0]hept-2-en-6-one when dissolved in FSO3H rearranged to give protonated 1-acetylcyclopentadiene. The mechanism and synthetic utility of these reactions is discussed.

Strong acid-catalyzed electrophilic ring expansion of oxetanes and sulfoxonium ylides

2021 ◽  
Vol 510 ◽  
pp. 111687
Author(s):  
Wenhao Yuan ◽  
Wenlai Xie ◽  
Jiaxi Xu
Keyword(s):  
Strong Acid ◽  
Ring Expansion ◽  
Acid Catalyzed

Acid-catalyzed rearrangement of hydroperoxides. II. Phenylcycloalkyl hydroperoxides

1968 ◽  
Vol 46 (9) ◽  
pp. 1561-1570 ◽  
Author(s):  
Glenn H. Anderson ◽  
James G. Smith
Keyword(s):  
Hydrogen Peroxide ◽  
Ferrous Sulfate ◽  
Phenyl Group ◽  
Ring Expansion ◽  
Steric Interaction ◽  
Ring Strain ◽  
Mineral Acids ◽  
Acid Catalyzed

The acid-catalyzed rearrangement of 1-phenylcycloalkyl hydroperoxides has been investigated using the cyclohexyl, cyclopentyl, and cyclobutyl compounds. Evidence was sought for rearrangement of the cycloalkyl group in competition with migration of the phenyl group during the reaction. Such a rearrangement would result in ring expansion of the cycloalkyl group to give, ultimately, products formed by cycloalkyl ring opening.No evidence for such a reaction was found in the case of 1-phenylcyclohexyl hydroperoxide; only the expected products, phenol and cyclohexanone, were detected. However, rearrangement of 1-phenylcyclopentyl hydroperoxide gave, besides the expected phenol and cyclopentanone, significant amounts of the ring-opened compound 4-hydroxyvalerophenone as its acetate. A second product, 1-phenylcyclopentene, arose by elimination of hydrogen peroxide from the hydroperoxide.1-Phenylcyclobutyl hydroperoxide proved to undergo ring expansion with great facility. Only the ring expanded products, 2-phenyl-2-tetrahydrofuryl hydroperoxide and its corresponding peroxide, could be isolated in the treatment of 1-phenylcyclobutanol with hydrogen peroxide using catalytic amounts of mineral acids. However, in the absence of catalysts, 1-phenylcyclobutyl hydroperoxide was formed in detectable amounts and its presence was demonstrated by decomposition with ferrous sulfate to butyro-phenone and 1,6-dibenzoylhexane.It seems reasonable that ring strain is the factor promoting the ring expansion of 1-phenylcyclobutyl hydroperoxide. In the case of 1-phenylcyclopentyl hydroperoxide, it is suggested that the steric interaction of the ortho hydrogens of the phenyl group with the cyclopentyl ring protons has the effect of slowing the migration of the phenyl group sufficiently that alkyl migration can occur to give the observed ring-opened products.

Transannular Ring Expansion in the Acid-Catalyzed Reaction of the Oxirane Derived from Spirocyclopropane-Substituted Bicyclo[2.2.2]oct-2-ene

1987 ◽  
Vol 120 (5) ◽  
pp. 705-712 ◽  
Author(s):  
Waldemar Adam ◽  
Elisabeth Crämer ◽  
Eva-Maria Peters ◽  
Karl Peters ◽  
Hans Georg Von Schnering
Keyword(s):  
Ring Expansion ◽  
Acid Catalyzed
Sign in / Sign up

Export Citation Format

Share Document