2,7-Dioxabicyclo[3.2.1]octan-3-one,6-(acetyloxy)-8-(decahydro-2,5,5-trimethylcyclopropa[d]naphthalen-2-yl)-,[1S-[1a,5a,6a,8R*(1aR*,2S*,4aR*,8aS*)]]-