While real estate titans Donald Trump and Gary Barnett have received attention for a litigious drama on Riverside South, the two developers may have a quieter rivalry transpiring downtown, in the western part of SoHo along Spring Street.

The Trump SoHo, a 45-foot glass condominium hotel, is slated to rise at Spring and Varick streets, bringing an influx of upscale residents to an area four blocks from the West Side Highway. Mr. Trump told The New York Sun that construction would begin soon, despite some delays caused by the discovery of human remains on the site.

Meanwhile, within view of Mr. Trump’s building site, Mr. Barnett also is investing in the future of the western edge of SoHo. He has purchased a group of contiguous properties on and around an outlet of the mattress retailer Sleepy’s, near Spring Street and Sixth Avenue, presumably for residential development.

The properties include 180 Sixth Ave., a five-story building just north of Sleepy’s, and could also include a three-story brick townhouse at 186 Sixth Ave. and an adjacent vacant lot. A spokesman for Extell Development Corp., George Arzt, said any development that might eventually be built in that area would be contextual and would stay within all the open space and setback requirements.

Mr. Barnett, whose developments include residential highrises on the Upper West Side and along West 42nd Street, also owns a stake in the site of the nearby Moondance Diner, which will soon be razed to make room for condos.

The Trump SoHo and the Barnett projects are part of a transformation taking place in western SoHo along Sixth Avenue, where several low-slung buildings are now attracting private investment. A former Mobil Station at 140 Sixth Ave. recently closed and is also slated for development.

“That stretch of Sixth Avenue, which had almost entirely passed by developers, clearly is now in the crosshairs,” the executive director of the Greenwich Village Society for Historic Preservation, Andrew Berman, said. He said the area has become more desirable as central SoHo has become more expensive and developers are pushed west.

The executive officer of Core Group Marketing, Shaun Osher, said the area around Sixth Avenue is desirable from a residential standpoint because it sits between SoHo and the West Village. Mr. Osher estimated that sales of residential condominiums in the area would range between $1,250 and $2,500 a square foot.

Antiques dealer David Stypmann, who sells decorative objects at David Stypmann Antiques, near Spring Street, said the Sleepy’s building is not particularly attractive. “At least Barnett will build a better building,” he said.

Plans for Trump SoHo, with its dark steel design, have drawn conflicting reactions. Mr. Stypmann said it was too large for the neighborhood. But Mr. Osher said Trump SoHo would have a powerful and positive effect on spurring business in the area.

Mr. Berman, whose organization has challenged the legality of the Trump SoHo development, said, “Nobody is going to throw themselves in front of the bulldozers to save the Sleepy’s.”

Still, Mr. Berman said new development should match the character of the neighborhood. His organization is advocating a proposed South Village Historic District, which, in its southernmost portion, would run to Watts Street from West Houston Street between Sixth Avenue and West Broadway.