A new route to perhydro- and tetrahydro- furo-2,3b furans via radical cyclisation
作者:M. Pezechk、A.P. Brunetiere、J.Y. Lallemand
DOI:10.1016/s0040-4039(00)83861-7
日期:1986.1
Perhydrofuro-2,3b furans have been prepared in high yield by radicalcyclisation of unsaturated bromo acetals. Their transformation into tetrahydro derivatives is described along with a radical annelation to 2,3- dihydrofurans by tributyltin iodoacetate.
Total Synthesis of Dihydroclerodin from (<i>R</i>)-(−)-Carvone
作者:Tommi M. Meulemans、Gerrit A. Stork、Fliur Z. Macaev、Ben J. M. Jansen、Aede de Groot
DOI:10.1021/jo991151r
日期:1999.12.1
The first total synthesis of the natural enantiomer of the insect-antifeedant dihydroclerodin (1) and lupulin C (40) has been achieved starting from (R)-(-)-carvone (2). In the applied strategy, the hexahydrofuro[2,3-b]furan moiety was introduced in an early stage of the synthesis. The correct configuration at C-9, C-11, C-13, and C-16 was established by application of a remarkably diastereoselective Mukaiyama reaction. The desired configuration at C-10 was obtained by catalytic reduction of the intermediate enone 21. After annulation of the second ring, the structural features at C-4, C-5, and C-6 were introduced. The successful finishing of the synthesis included a Chugaev elimination to give the exocyclic double bond at C-4 that is present in lupulin C. Oxidation of this double bond with m-CPBA afforded dihydroclerodin.