With no explanation, label each line with "O", "other-chemicalthing", "person-scholar", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart" or "building-airport" preceded by ":".
A
naturally
occurring
[
5
]
-ladderane
lipid
,
named
pentacycloanammoxic
acid
,
has
been
synthesized
by
Corey
and
coworkers
.
A:O
naturally:O
occurring:O
[:other-chemicalthing
5:other-chemicalthing
]:other-chemicalthing
-ladderane:other-chemicalthing
lipid:other-chemicalthing
,:O
named:O
pentacycloanammoxic:other-chemicalthing
acid:other-chemicalthing
,:O
has:O
been:O
synthesized:O
by:O
Corey:person-scholar
and:O
coworkers:O
.:O