TY  - JOUR
A1  - Fudickar, Werner
A1  - Vomdran, Katja
A1  - Linker, Torsten
T1  - Auxiliary controlled singlet-oxygen ene reactions of cyclohexenes
JF  - Tetrahedron
N2  - The photooxygenation of homochiral cyclohexene ketals, which are easily available from 2-cyclohexenone and L-tartrates, affords hydroperoxides and after reduction the corresponding allylic alcohols in good yields and high regioselectivities. This can be rationalized by electronic repulsions in a perepoxide intermediate and provides evidence for unfavorable 1,3 diaxial interactions with a dioxolane oxygen atom. Only low stereoselectivities were observed, due to the flexibility of the cyclohexene ring. However, the diastereomers could be separated and after cleavage of the auxiliary, 4-hydroxy-2-cyclohexen-1-one was isolated in enantiomerically pure form, which can serve as a building block for natural product synthesis.
KW  - singlet oxygen
KW  - auxiliary control
KW  - regioselectivity
KW  - stereoselectivity
Y1  - 2006
U6  - https://doi.org/10.1016/j.tet.2006.07.104
SN  - 0040-4020
VL  - 62
IS  - 46
SP  - 10639
EP  - 10646
PB  - Elsevier
CY  - Oxford
ER  -