Question

5) Propose a synthesis of the following molecule, which will involve using an acetal protecting group, forming a Grignard reagent and performing a nucleophilic attack on a separate carbonyl compound. This will be a multi-step synthesis.

Answer 1

OH © + oH Mg-BY Acetaldehyde From above sebeynthes's imaginou backward synthesis) by the treatment & Grignard reagent with

cotalpaydo we will got the product ③ orgar OH side Reaction: The problem is self condensation op Gorgnard's reagent which contains -vely changed Carbon bowl outin same molecule r ] LM9-B Mg-

To avold this unwanted reaction, a we have to protect Coorbonyl group piest, then convert the protected Carbonyl compound into Goignard's seagent, which will at tack on Acetaldehyde to give the desired reaction. finally the product is depoo tected. OH OH Mg, day Elo -Bar o-mg Bor

DE Has Mechanism Step 1: Powtecten op Carbonyl group 1/ 1 o 1 He yanix B Hö: 4

-B protected Carbonyl compound step : tormation of Gaignard's reagent? +MgOO -Br

step.al attack op Grignards reagent on Acetaldehyde: By step. Is of a pretola Hydroly six oxide ton

그 HD 0 : rg Br. Hö: 해 Hit | 01 - 200 11 201 - 0 개

OH 201 해 H30 | - OH