Question

If I could get some assistance with this it would be much appreciated!!

What is the best route for converting the alcohol to the ether as shown below using a substitution reaction or a sequence of substitution reactions while preserving the stereochemistry at the chiral center? OH осн. a. LICH b.i. HCl; il CH2OH c. i. HCI; il NaOCH3 d. NaOCH3 CH3OH f. i. PC13: il. NaOCH3

Answer 1

OH (i) PC13, (ii) NaOCH3 OCH; Here the thing we have to keep in mind is the stereochemistry of the product. The _OH in the starting is up and the OCH3 in the product is also up. CI H OH CI CI this Cl- attacks from down the plane This follows SN2 mechanism and the stereochemistry changes. Means the newly introduced chloride group is down the plane. OCH NaOCH3 The OCHg attacks from above the plane and as chlorine is a good leaving group it goes out to form the product. Answer: f. (i) PCl3, (ii) NaOCH;