Draw all stereoisomers formed in each reaction.

a.

b.

c.

d.

Cis-trans isomerism is employed for a simple system like the disubstituted alkenes, whereas the E-Z isomerism is utilized for higher systems like the trisubstituted alkenes.

Carbonyl compounds get subjected to several reactions, and a critical reaction is nucleophilic addition. Cyanohydrins are formed by the nucleophilic addition of a carbonyl compound with sodium cyanide and an acid like HCl.

a.The given compound is an aldehyde which undergoes reaction with an aldehyde leading to the formation of alkenes,(E)-oct-4-ene and (Z)-oct-4-ene. The reaction can be given as:

Stereoisomers of reaction a

b.The given compound is a ketone that undergoes nucleophilic addition with NaCN, leading to the formation of cyanohydrin. The reaction can be given as:

Stereoisomers of reaction b

c. The given reaction is a hydride reaction of a ketone. The addition of carbanions to carbonyl compounds results in the formation of a mixture of stereoisomers. The reaction can be given as:

Stereoisomers of reaction c

d. The given reaction is the reaction of a hemiacetal with an alcohol and an acid. The stereoisomers of the reaction can be given as:

Stereoisomers of reaction d