Supply missing reagent A and product B in the following synthetic scheme. No stereochemistry needed. Product B is propranolol, an antihypertensive agent used in the treatment of high B.P.
Seems like the first reaction is a Williamson ether reaction where we will use NaH to deprotonate that -OH group. Then we can now add an alkyl halide that fits the given product. I drew A below.
For B, this is a base-catalyzed epoxide ring opening that favor addition to the LEAST substituted carbon (kinetic control). So the amine gets attached to the least substituted C while -OH will be present at the secondary carbon. I also drew both enantiomers of B.
You can also watch the related reactions here:
Williamson Ether Synthesis:https://www.clutchprep.com/organic-chemistry/ether-synthesis/?c_id=453
Base-Cat Epoxide opening:https://www.clutchprep.com/organic-chemistry/epoxide-ring-opening-2/?c_id=453
Hope that helps