Reductive cleavage of tetrahydrofuryl sulfur-substituted oxiranes: application to the formal synthesis of Kumausyne and Kumausallene.
[reactions: see text] Readily available sulfinyl and sulfonyl tetrahydrofuran methanol derivatives have been transformed efficiently into a variety of substituted tetrahydrofuryl alcohols by treatment with (PhSe)2 in the presence of an excess of NaBH4. Alternatively, oxirane cleavage with MgI2 produces the related ketones, amenable to stereocontrolled reduction. This reductive cleavage methodology has been applied to short formal syntheses of trans-Kumausyne and Kumausallene.
Fernández de la Pradilla
Roberto
R
Instituto de Química Orgánica, CSIC, Juan de la Cierva, 3, 28006 Madrid, Spain. iqofp19@iqog.csic.es
Alhambra
Carolina
C
Castellanos
Alejandro
A
Fernández
Jorge
J
Manzano
Pilar
P
Montero
Carlos
C
Ureña
Mercedes
M
Viso
Alma
A