DEMI  MOORE is so desperate for love she’s trying to woo back one-time lover Leonardo DiCaprio – but he wants NOTHING to do with her, say sources.

The 49-year-old actress, who’s still reeling from her painful split from “Two and a Half Men” hunk Ashton Kutcher, has been e-mailing and calling Leo, hoping to reignite the spark they shared more than 15 years ago, the sources add. And she apparently doesn’t even care that he’s in a serious relationship with sexy Victoria’s Secret model Erin Heatherton!

As The ENQUIRER exclusively reported in 1997, Leo spent the night with Demi in her and former husband Bruce Willis’ Malibu home during a time when the couple’s marriage was on its last legs. But insiders say Demi is making WAY more out of that than it was – and Leo has no desire to revisit the past.

“Demi is so lonely and hungry for love,” a source revealed. “After all these

 years, she’s romanticized what really amounted to just a fling.

“She’s infatuated with the idea of her and Leo becoming Hollywood’s hottest power couple. She’s lonely and facing her 50th birthday this month, so she’s looking to rejuvenate her love life and career.”

According to the source, Demi has been spending more time in New York recently, where 37-year-old heartthrob Leo is filming “The Wolf of Wall Street.”

“Unfortunately for Demi, Leo is giving her the big-time blow off,” continued the source. “He won’t even get together with her for coffee!”

Demi has been struggling since her six-year marriage to Ashton fell apart last November, and she’s devastated that he’s moved on to a hot-and-heavy romance with his “That ’70s Show” co-star Mila Kunis. She entered rehab in early 2012 for prescription pill and eating disorder-related problems following a physical and emotional meltdown.

“Demi’s dream is to find a young, successful guy who can help elevate her back to her past glory,” added the source. “But she’s barking up the wrong tree with Leo.

“He idolized her when he was in his 20s and fresh off the blockbuster success of “Titanic,” but now Leo thinks Demi is too old.

“He doesn’t want to get tangled up in her messy life.”