Novel Rearrangement of Tertiary Fenchyl Alcohols with Sulfuric Acid in Acetonitrile

• Autorzy: Wełniak M.
• Języki publikacji: EN

Abstrakty

EN

The influence of steric hindrance on rearrangements of tertiary 2-fenchyl cations under the Ritter reaction conditions (CH3CN/H2SO4) has been described. Depending on the branching of alkyl substituents at the C-2 position, the reaction time and temperature, different reaction courses have been observed. After 10 minutes at -20 to -15°C alcohol 2 (R = iso-Am) gave alkenes 7, whereas a pair of amides 8 and 9 for 24 hours at ambient temperature as a result of successive exo-3,2-methyl shift,Wagner-Meerwein rearrangement and endo-6,2-hydride shift. Alkene 10 was obtained as a primary product from alcohol 3 (R = iso-Bu) after 10 minutes at -20 to -15°C. When the same reaction was continued for 24 hours at room temperature, amide 12 has been obtained as the only product. It was explained by the operation of endo-6,2-hydride shift after protonation of alkene 10 and further reaction with acetonitrile. In the case of alcohols 4-6 with bulky isopropyl, sec-butyl and 2-sec-amyl substituents, a novel rearrangement to tetrasubstituted alkenes containing the bicyclo[3.1.1]heptane skeleton have been notified. The mechanistic proposals for the investigated reaction are presented.

Słowa kluczowe

EN

terpenes; fenchyl system; Ritter reaction; rearrangements

• Wydawca: Polskie Towarzystwo Chemiczne
• Czasopismo: Polish Journal of Chemistry
• Rocznik: 2002
• Tom: Vol. 76 / nr 1
• Strony: 37--44
• Opis fizyczny: Bibliogr. 18 poz., rys.

Twórcy

autor

Wełniak M.

• Faculty of Chemistry, Nicolaus Copernicus University, 87-100 Torun, Poland

Bibliografia

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