Practical synthesis of 1,5-dimethyl substituted conjugated polyenes from geranyl acetate

A protocol to synthesize 1,5-dimethyl substituted conjugated polyenes via dehydrogenation of geranyl acetate was established. C5 unit elongation to multi-1,5-dimethyl substituted conjugated polyenes was also achieved via Horner–Wadsworth–Emmons olefination in good yields and good selectivities.