We describe the development of a strategy for the construction of the quaternary carbon stereocenter of αtertiary amines. This strategy highlights a site-selective C−H functionalization involving an alkoxy-radical-triggered 1,5hydrogen transfer (1,5-HAT) reaction of a conformationally fixed spiro-compound derived from trishydroxymethylaminomethane (Tris). The utilization of this strategy enabled an enantioselective total synthesis of myriocin, a naturally occurring sphingosine analog that displays potent immunosuppressive activity.