Spiro[3-cyclohexene-1,4'(3'H)-[1H-7,9a]methanocyclohepta[c]pyran]-1',2,9'(4'aH)-trione,5',6',7',8'-tetrahydro-6-(hydroxymethyl)-5,5,8'-trimethyl-, [4'S-[4'a(S*),4'ab,7'a,8'b,9'aa]]-