penilactone D + o-quinone methide + H(+) <=> penilactone B
penilactone d + o-quinone methide + h(+) <=> penilactone b
penilactone D + o-quinone methide + H(+) <=> penilactone B
penilactone d + o-quinone methide + h(+) <=> penilactone b