Retrosynthetic Analysis 1 CH3 c-CH3 CH3 C-CH CH3 C-CH3 H H CHa CH3H H H HH Cationic -? Intramolecular Cyclization aldolldehydration CH3 intramolecular aldol/dehydration 6 00 o WiTtig reaction 10Retrosynthetic Analysis 1 O CH3 H CH3 C O CH3 H H CH3 CH3 Intramolecular aldol/dehydration O CH3 H CH3 C O CH3 H H CH3 H CH3 C O CH3 H H O H H H O OH O O Cationic-? Cyclization Intramolecular aldol/dehydration O O O O Wittig reaction O O O O O PPh3 + 1 2 3 5 4 6 7 8 9 10