Complex sentence: In 1978, Trump consummated his first major real estate deal in Manhattan, purchasing a half-share in the decrepit Commodore Hotel, largely funded by a $70 million construction loan jointly guaranteed by Fred Trump and the Hyatt hotel chain.
Split into simpler sentences: In 1978, Trump consummated his first major real estate deal in Manhattan when he purchased a half-share in the decrepit Commodore Hotel. The purchase was largely funded by a $70 million construction loan that was jointly guaranteed by Fred Trump and the Hyatt hotel chain.