5,11,17,25-tetrakis(1-methylethyl)-21-oxapentacyclo[21.3.1.1~3,7~.1~9,13~.1~15,19~]triaconta-1(27),3(30),4,6,9(29),10,12,15(28),16,18,23,25-dodecaene-27,28,29,30-tetrol