[science123]

Using reactions from undergrad Organic chemistry. Allowed starting materials are cyclohexane, benzene and alcohol of 3 carbons or less.

[discodermolide]

You can shorten it by starting from benzoic acid, hydrogenation with Nishimura's catalyst will give cyclohexane carboxylic acid thus avoiding the Grignard reaction with formaldehyde, make the acid chloride and you are back on track.