Question

10. We learned in class that epoxides undergo ring-opening reactions in the presence of strong nucleophiles. Grignard reagents can serve as suitable nucleophiles for ring-opening of ethylene oxide. This reaction serves as an efficient strategy for adding carbon chain length and a hydroxyl functionality for synthetic purposes. RMgX + BVOH + HOMEX Grignard reagent ethylene oxide 1 alcohol (after aqueous work-up) a. Draw a mechanism for the reaction of isopropyl magnesium chloride with ethylene oxide. b. Show how a Grignard reaction with ethylene oxide could be used in a multi-step synthesis of the compound below, starting from bromocyclohexane and using reagents of your choosing c. Grignard reactants also react slowly with oxetane in a similar fashion. Propose a mechanism for this reaction, and suggest why oxetane reacts with Grignard reagents even though most ethers do not. RMgX RM Max ri oxetane Grignard reagent salt of 1' alcohol

Answer 1

Due to ring strain four membered ring (Oxetane ) also react with Grignard reagent and ring opening occur.

Salotfou - (a) Goignard reagent is used for sing opening as given above because it 18 a good nucliophile l a isopropyl maguziune choseido evathylene oxide си, см2. z me cuz omgce Ma Chh ana cu care product) R4 Mg/ether MaBr orgar Hoft -cu-CH₂-OH con oxidation Кся,04 Aue (product)

+5 I Rgx + to R7 00 Because it has also thing stuain like ethelene oxide but in 3-memberid being more train hence ecate in case of Oxetane is clower compare to ethelene oxide. But дис tegeed a gde sІзаји рас+гом осең лау.