SAN FRANCISCO — Lawyers for Facebook Inc. founder Mark Zuckerberg are fighting a lawsuit alleging he scammed a real-estate developer out of a multimillion-dollar property behind his home in an upscale Palo Alto neighborhood.

Plaintiff Mircea Voskerician, who buys and rebuilds old Bay Area homes, alleges he sold Zuckerberg his right to a property at a huge discount in 2012 because Zuckerberg promised to introduce him to Silicon Valley’s power players. Zuckerberg never followed through, nor did he intend to, plaintiffs attorneys allege, which they say is “despicable.”