2H-Oxireno[e][2]benzoxacyclotetradecin-6,12(3H,7H)-dione, 8-chloro-1a,14,15,15a-tetrahydro-3,9,11-trihydroxy-14-methyl-, (1aR,3S,14S,15aR)- AIDS-181727 AIDS181727 Pochonin B