# What is the number of stereoisomers for hex-4-en-2-ol?

For the following compound, find

1. Total number of stereoisomers
2. Number of optically active stereoisomers
3. Total number of fractions on fractional distillation of all stereoisomers There is a chiral carbon marked with "*" in the compound. The compound is thus chiral and is optically active. The configuration at the chirality centre can either be R or S. There is also a double bond in the compound and cis-trans (geometrical isomerism) is possible here. So using basic permutations there are totally $$2\times2=4$$ stereoisomers (optical and geometrical).

Since there is a chirality centre the compound exists in right-handed and left handed systems and thus is optically active. Thus all the 4 stereoisomers are optically active.

Out of R-cis, R-trans, S-cis, S-trans isomers there are two pairs of diastereomers - R-cis, S-trans and R-trans, S-cis - so there are 2 fractions obtained due to fractional distillation.

1. Total number of stereoisomers = 4
2. Number of optically active stereoisomers = 4
3. Total number of fractions on fractional distillation of all stereoisomers = 2

Are my approach and my answers right?