Hyperconjugative Control by Remote Substituents of Diastereoselectivity in the Oxygenation of Hydrocarbons.
The oxidation of 2-substituted adamantanes (2) with TFDO (1) is reported. The data show a stereodifferentiation of the chemical environments induced by remote electron-withdrawing substituents which produces remarkable Z/E diastereoselectivity in the oxidation of the tertiary C(5)-H and C(7)-H bonds. The results show a bell-shaped correlation between the Z/E stereoselectivity and the substituent constant sigma(I), which is interpreted in terms of hyperconjugative stabilization of the diastereomeric transition states.
González-Nuñez
ME
Departamento de Química Orgánica, Universidad de Valencia, Avda. V. Andrés Estellés s/n, 46100-Burjassot (Valencia), Spain.
Royo
J
Castellano
G
Andreu
C
Boix
C
Mello
R
Asensio
G