Скачать или смотреть Seyferth-Gilbert Homologation

The Seyferth-Gilbert Homologation allows the conversion
of carbonyl compounds to the corresponding terminal or
internal alkynes with the aid of alpha-diazophosphonates
under basic conditions.

Reaction mechanism:
1. Deacylation of the Ohira-Bestman Reagent by a mehoxide group.
2. The resulting carbanion attacks the carbonyl group of the aldehyde.
3. The oxaphosphetane-type intermediate breaks down to afford
a diazoalkene.
4. The diazoalkene loses dinitrogen in an alpha-elimination reaction
while the alkylidene carbene undergoes 1,2-shift to give the
corresponding alkyne.

References:
NROChemistry: https://nrochemistry.com/seyferth-gil...