TaskExtensions.cs

using System;
    using System.Threading;
    using System.Threading.Tasks;

    public static class TaskExtensions
    {
        public static T RunTaskSynchronously<T>(this Task<T> task)
        {
            using (NoSynchronizationContextScope.Enter())
            {
                return task.Result;
            }
        }

        //http://stackoverflow.com/a/28307965/6618364
        private static class NoSynchronizationContextScope
        {
            public static Disposable Enter()
            {
                var synchronizationContext = SynchronizationContext.Current;
                SynchronizationContext.SetSynchronizationContext(null);
                return new Disposable(synchronizationContext);
            }

            public struct Disposable : IDisposable
            {
                private readonly SynchronizationContext synchronizationContext;

                public Disposable(SynchronizationContext synchronizationContext)
                {
                    this.synchronizationContext = synchronizationContext;
                }

                public void Dispose()
                {
                    SynchronizationContext.SetSynchronizationContext(this.synchronizationContext);
                }
            }
        }
    }