Naturally occurring substances containing a
cis-fused tetrahydrochromeno[3,4-
b]chromene
nucleus. Many rotenoids contain an additional ring, e.g rotenone:
Source:
PAC, 1995, 67, 1307
(Glossary of class names of organic compounds and reactivity intermediates based on
structure (IUPAC Recommendations 1995))
on page 1364