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 ":".
The
final
cyclobutane
is
formed
by
a
Wolff
rearrangement
,
and
the
alkyl
chain
is
installed
by
a
Wittig
olefination
.
The:O
final:O
cyclobutane:other-chemicalthing
is:O
formed:O
by:O
a:O
Wolff:person-scholar
rearrangement:O
,:O
and:O
the:O
alkyl:other-chemicalthing
chain:other-chemicalthing
is:O
installed:O
by:O
a:O
Wittig:other-chemicalthing
olefination:other-chemicalthing
.:O