peniphenone D => (R)-5-methyl-tetronate + o-quinone methide
peniphenone d => (r)-5-methyl-tetronate + o-quinone methide
peniphenone D => (R)-5-methyl-tetronate + o-quinone methide
peniphenone d => (r)-5-methyl-tetronate + o-quinone methide