2,2-Dimethyl-propionic acid 2-((4aS,5S,7S,8aR)-7-formyl-2,2,4a-trimethyl-tetrahydro-pyrano[4,3-d][1,3]dioxin-5-yl)-ethyl ester

2,2-Dimethyl-propionic acid 2-{(4aS,5S,7S,8aR)-7-[(E)-4-(tert-butyl-diphenyl-silanyloxy)-but-1-enyl]-2,2,4a-trimethyl-tetrahydro-pyrano[4,3-d][1,3]dioxin-5-yl}-ethyl ester