Base-Induced Rearrangement of Perhydronaphthalene-1,4-diol Monosulfonate Esters to 11-Oxatricyclo[5.3.1.02,6]undecanes. Total Synthesis of Furanether B

It is observed that mesylate 1 on exposure to Li(Ot-Bu)3AlH in refluxing toluene rearranges selectively to the 11-oxatricyclo[5.3.1.02,6]undecane derivative 3. A similar rearrangement, leading to a bridged tricyclic ether (14 → 5), has been used as the key to the total synthesis of furanether B (4), a naturally occurring lactarane sesquiterpene, with the readily available ketone 8 as the starting material. Completion of the synthesis of the natural product is accomplished by an annulation method based on a Pummerer-induced cyclization reaction.