Question

in synthesis path B, two products with the same sum formula are formed, draw these two products, and describe how they relate to each other, include reaction mechanism

H2O, H2S04 Br2 C10H180 b) Skisser en reaksjonsmekanisme for reaksjonen i syntesevei A og beskriv hvorfor dette produktet dannes. (10 p) I syntesevei B dannes det to produkter med samme summeformel. Tegn disse to produktene og beskriv hvordan de forholder seg til hverandre. (8 p) c)

Answer 1

Adition of bromine to alkene is a stereosoecific reactoon. Cis-alkene gives only two enantiomers while trans-alkene gives only meso isomer.

The given cyclic compound is has a cis-double bond ,so it gives only two enantiomers. The structure of two products ( they are non-superimposable mirror images to each other) are given below.

Mechanism of the reaction ;

B1 2 Emantiomen mager

The first step is an electrophilic addition by bromine on the double bond. It forms a cyclic three membered intermediate known as bromonium ion.  

In the second step Br^- attacks on either side of carbon of the bridged ion at equal proportion to form two different anti addition products.  

(cis- AlKene)

Mecbani 8m 391 SLow Bn