(4R,5R,6R)-6,7-Bis-(tert-butyl-dimethyl-silanyloxy)-2,2,4-trimethyl-1,3-dioxa-spiro[4.4]non-7-ene

(4S,5R)-2,2,5-trimethyl-1,3-dioxolane-4-carbaldehyde

(E)-4-((4R,5R)-2,2,5-Trimethyl-[1,3]dioxolan-4-yl)-but-3-en-2-one

4-((4R,5R)-2,2,5-Trimethyl-[1,3]dioxolan-4-yl)-butan-2-one

(4R,5S)-2,2,4,7-Tetramethyl-1,3-dioxa-spiro[4.4]non-6-ene