Question

Please analyze this reaction for me by stating details about what happened, which group was the protecting group, and how it lead to the final product being formed.

In this experiment, you will perform a stereoselective reaction by protecting a 1,3-diol as an acetal. The classical acetalization reaction involves either a diol or multiple alcohols and a carbonyl species such as an alcohol or ketone. This process requires efficient removal of water from the reaction, which can be experimentally challenging. Instead, you will perform a transacetalization reaction. By using benzaldehyde dimethyl acetal as an aldehyde surrogate, methanol is formed as byproduct in a reaction with 2-methylpropane-1,3-diol: this process is far easier to drive to completion. As you are forming a six- membered ring, multiple isomers are possible and you will analyze the structure of your product by 1H NMR spectroscopy. O-CH3 catalytic S., CH2 HOY OH -CH3 H C CH3 + 2x CH3OH CH3 HO3S Figure 1. Reaction Scheme.

Answer 1

- In this expesiment the 1,3-diol is a substrate in which the two - on groups needs to be protected - so 2-Methylpropan-1,3-diol - - HO T OH CH₃ is the supistate. To protect the cliol, we need ben benzaldehydo or it's desvative to protect. Sa T o -cHg is used as protecting benzaldehepte dimethyl acela group, the och benza Benzaldehyde - dimethyl aceted as protecting agent. - To protect the did with benzaldehyde dimethilacetal, we need acid catalant - and therefore Camphorsulfonic acid is used as catalyst - Host Camphor sulfonic acid as - In this reaction, the protonated OCH of benzaldehyde dimethylacetal acts as leaving group, which leaves as methano (CH₃OH) OCH - Ento RIX H- e - OCH सर पर । Getty oth -CH3 HOH OH IOH TINTICH Scanned with CamScanner