(±)-trans,cis-4-Hydroxy-5,6-di-O-isopropylidenecyclohex-2-ene-1-one: Synthesis and Facile Dimerization to Decahydrodibenzofurans
journal contributionposted on 04.03.2011, 00:00 by Victoria L. Paddock, Robert J. Phipps, Almudena Conde-Angulo, Araceli Blanco-Martin, Carles Giró-Mañas, Laetitia J. Martin, Andrew J. P. White, Alan C. Spivey
An efficient synthesis of (±)-trans,cis-4-hydroxy-5,6-di-O-isopropylidenecyclohex-2-ene-1-one (3) has been developed from acetonide-protected meso-1,2-dihydrocatechol derivative 1 via photooxygenation, then Kornblum−DeLaMare rearrangement. The product is unstable unless its 4-hydroxy group is protected, as it undergoes facile dimerization in solution to a 1:1 mixture of diastereoisomeric decahydrodibenzofurans 8 and 9. A new synthesis of the dihydrocatechol 1 from 1,3-cyclohexadiene has also been developed.