Muscarine is a poisonous substance present in the mushroom Amanita muscaria. Its structure is represented by the

Question:

Muscarine is a poisonous substance present in the mushroom Amanita muscaria. Its structure is represented by the constitution shown.

(a) Including muscarine, how many stereoisomers have this constitution?
(b) One of the substituents on the ring of muscarine is trans to the other two. How many of the stereoisomers satisfy this requirement?
(c) Muscarine has the configuration 2S,3R,5S. Write a structural formula or build a molecular model of muscarine showing its correct stereochemistry.