7-[6-(2-benzyloxyethyl)-2,2,4-trimethyl-[1,3]dioxan-4-yl]-6-(tert-butyldimethylsilanyloxy)hept-1-en-4-ol

9-[6-(2-benzyloxyethyl)-2,2,4-trimethyl-[1,3]dioxan-4-yl]-8-(tert-butyldimethylsilanyloxy)non-1-ene-4,6-diol