A PhSeCl-mediated allylic oxidation of prenyl moiety: a convenient method for the construction of 3-isopenten-2-ol unit.

A phenylselenenyl chloride (PhSeCl)-mediated allylic oxidation to give allylically rearranged alcohol has been developed. A possible mechanism for the present reaction is generation of allylic selenide from prenyl moiety via [1,3]-sigmatropic rearrangement, followed by oxidation and [2,3]-sigmatropic rearrangement to afford 3-isopenten-2-ol.

Synthetic study of diversifolin: the construction of 11-oxabicyclo[6.2.1]undec-3-ene core using ring-closing metathesis.

Stereoselective synthesis of a potential intermediate bearing 11-oxabicyclo[6.2.1]undec-3-ene core, a common scaffold of biologically active germacrane-type sesquiterpenes, has been achieved. Synthetic features involve formal 1,3-asymmetric induction, unusual ring-closing metathesis constructing a 10-membered carbocycle system, and unique lactone transposition.