Depending on your definition of "raw materials" the 4th level spell Fabricate (pg. 239 of PHB) might be of use. It only takes 10 minutes to cast.

You convert raw materials into products of the same material.

I see 2 ways that this spell could be used to serve your purpose, given that you have an open-minded GM.

1. On the Flesh - Use Fabricate just on the flesh to make nice furniture (or other products) made out of flesh in a different space away from the body. This method should leave the skeleton behind. This might be a too liberal use of the term "raw materials", however it does say in its description that works on organic material.
2. On the Bones - Use Fabricate on the bones to recreate the skeleton in a different space. Bone might considered more raw material than flesh. However, since you have to see the material, you'd need to slice up the body quite a bit to see all the bones requiring more time. Though here's a benefit, if you just had time to gather one bone at a time, you could use an assortment of bones to make a full skeleton at a later time. Also, you could make small-sized skeletons this way if so desired.

As an added note, I'm using this question here to justify that Fabricate's no-creature condition would work in this case: Is a dead creature's body considered an “object”?

Depending on your definition of "raw materials" the 4th level spell Fabricate (pg. 239 of PHB) might be of use. It only takes 10 minutes to cast.

You convert raw materials into products of the same material.

I see 2 ways that this spell could be used to serve your purpose, given that you have an open-minded GM.

1. On the Flesh - Use Fabricate just on the flesh to make nice furniture (or other products) made out of flesh in a different space away from the body. This method should leave the skeleton behind. This might be a too liberal use of the term "raw materials", however it does say in its description that works on organic material.
2. On the Bones - Use Fabricate on the bones to recreate the skeleton in a different space. Bone might considered more raw material than flesh. However, since you have to see the material, you'd need to slice up the body quite a bit to see all the bones requiring more time. Though here's a benefit, if you just had time to gather one bone at a time, you could use an assortment of bones to make a full skeleton at a later time. Also, you could make small-sized skeletons this way if so desired.

As an added note, I'm using this question here to justify that Fabricate's no-creature condition would work in this case: Is a dead creature's body considered an “object”?