In broad strokes, and in a formal retrosynthetic sense, titanacyclopropane 1 behaves like a 1,2-dianion which adds into the ester twice: after the first addition into the ester, the resultant tetrahedral intermediate 2 collapses to give β-titanio ketone 3, which undergoes a second intramolecular addition to give the titanium salt of the cyclopropanol (4).
Broadly speaking, and in a formal retrosynthetic approach, titanacyclopropane 1 functions as a 1,2-dianion that adds into the ester twice: after the first addition into the ester, the resultant tetrahedral intermediate 2 collapses to yield β-titanio ketone 3, which then undergoes a second intramolecular addition to produce the titanium salt of the cyclopropanol (4).