As for synthetics Iâ€™m out of my comfort zone so Iâ€™ll leave that to others but on naturals Iâ€™m more at home.
First my recommendations would be have a look at Coconut â€“ absolute, tincture and natural, all will without doubt be useful to you but I think finding the absolute will be one heck of a challenge.
As for the Coconut Oil I only have experience of fractionated material from my aromatherapy days which is liquid from memory and something many in aromatherapy use as a base for their blends â€“ its stable, has a long shelf life, and I think is mostly odourless. Personally Iâ€™d be more inclined to use organic grain alcohol with the coconut materials mentioned above along with your Aldehyde C18 to create your perfume.
With Cedarwood I personally am not sure at all, for me I think you get the best out of the Cedarwood oils mentioned when used with other woods and also with florals perhaps. Massoia Bark is indeed coconut like, think coconut ice cream, especially in its top note but it does develop greatly and I know a fair few have said to me that is has a herbal/vegetative note in its heart through to drydown. Also I think Massoia Bark is prohibited by the IFRA. One wood that maybe of some use to this project that is very sweet wood creamy and Iâ€™m sure that could help you create a Coconut masterpiece is Siam Wood - Fokiena hodginsii - when used along with the other materials.
Anyhoo, all the best with this Waywardspirit. Adam