Devise a synthesis for the following alkenes using the Wittig reaction starting with an alkyl halide and a ketone or an aldehyde.

Wittig reaction synthesis of alkenes from alkyl halide and ketone/aldehyde.

Wittig reaction synthesis pathways for alkenes using alkyl halides and ketones/aldehydes.

Wittig reaction mechanisms for synthesizing alkenes from alkyl halides and ketones/aldehydes.

Wittig reaction synthesis of alkenes from alkyl halides and ketones/aldehydes.