Casting to a derived type in a LINQ to Entities query with Table Per Hierarchy inheritance

I have a LINQ to entities model with Table Per Hierarchy inheritance. I have a query over the base type, and I want to do specific type-dependent logic. For example:

IQueryable<BaseType> base = ...

// this works fine
var result = base.Select(b => b is DerivedType1 ? 1 : 2).ToList();

// this doesn't compile to SQL
var result2 = base.Select(b => b is DerivedType1 ? ((DerivedType1)b).DerivedProperty : null).ToList();

Is there any way to do something like this without processing IQueryables of each derived type separately:

// I'd rather not do this:
var resultA = base.OfType<DerivedType1>().Select(d => d.DerivedProperty);
var resultB = base.OfType<DerivedType2>().Select(d => default(int?));
var result = resultA.Concat(resultB).ToList();