A convergent synthetic pathway for access to the functionalized
(±)-9-decanolides is described, using a [4+2] bicyclic heterocycloadduct
as the key intermediate. Thus, the exo adduct (±)-10 led to the hemiacetal (±)-14a via a 4-step sequence. Free radical
oxidation of (±)-14a by means
of iodine and iodosobenzene diacetate under UV light gave the model
9-decanolide (±)-15 in 53% yield.
9-decanolides - bicyclic adducts - Diels-Alder
reactions - radical reactions - macrocycles - lactones