135643-41-3 3,4,5,13-Tetrahydro-3H-2-benzothieno(5,4-d)naphtho(1,2-b)pyran 3,4-Tbnp 3H-Benzo(h)(2)benzothieno(4,5-c)(1)benzopyran, 3a,4,5,13-tetrahydro-, (+-)-