The following solves part of the problem (as usual I came up with the answer 5 seconds after posting the question). However I'd still like to be able to not use a custom comparer as it seems pretty pointless.
IEnumerable<MyMeasure> interList =
MyMeasure.Distinct(new MyMeasure.NameComparer())
.Where(cmo => cmo.CompanyMeasureName
.ToLower()
.Contains(term.ToLower())).Select(m => m.CompanyMeasure);