Jewish teens leaned their skullcap-covered heads into the doorway of the kosher pizzeria on the Rue des Rosiers, hoping to order one of Moshe Benjamin Engelberg’s thin-crusted pizzas.

But Engelberg shook his head. After 27 years, he has lost faith in his neighborhood, a home to French Jews since the Middle Ages, and is shutting down, depriving the district of one of its remaining old world-style kosher restaurants.

The district has been losing a vital chunk of its Jewish character to high-end designer labels in a slow transformation that residents say is reaching a turning point. Local officials estimate that as many as 20 Jewish shops in the compact quarter have given way to clothing stores in the past four years.

“What remains is a sort of optical illusion,” said Jean Laloum, a historian at France’s National Center for Scientific Research.

“Tourists come to visit a sort of ghetto with an identity … which they read about in the guidebooks, but which today, in reality, is gone.”

The Rue des Rosiers quarter, nestled in the chic Marais district north of the Seine River, has been home to French Jews for centuries.

Until recently, this former stomping ground for poor Eastern European and then North African Jewish immigrants was a densely packed network of institutions and traditional shops attracting Jewish shoppers from Paris and its environs — and tourists from around the world — despite residents progressively migrating away.

Even the Nazi occupation couldn’t snuff out the area’s reputation as the city’s Jewish pole of reference.

More than 1,000 people from roughly nine small streets centered around Rue des Rosiers were deported to death camps during World War II. Others were allowed to remain if they abided by discriminatory codes, such as following curfews and wearing a yellow star. Today France has Western Europe’s largest Jewish community, at approximately 500,000.

Known as the “neighborhood guardian” in the local Lubavitch community because he keeps the keys to a nearby synagogue, Engelberg recently fielded protests against his departure and concerns he was abandoning those left behind.

“It’s very delicate,” he acknowledged. “People don’t want it to change.”

After the city required Engelberg to make costly upgrades to the restaurant, he consulted a rabbi for advice and concluded that renovating wasn’t worth the trouble.

“It’s not the feeling of the ghetto anymore, it’s the feeling of something modern, without a soul,” Engelberg said.

Instead, he plans to sell to the highest bidder and perhaps open another pizzeria in a working class neighborhood in northern Paris.

He is not alone.

The emblematic Yiddish diner Jo Goldenberg’s, which attracted visitors from all over the world and was targeted in a bombing in 1982, shut down two years ago, and will most likely be replaced by a designer clothing store, according to Franck Desnoyers, charged with selling the space. Across the street, a trendy H&M clothing store will open this fall, confirmed Dominique Bertinotti, the district’s Socialist mayor.

The Rue des Rosiers is part of the larger surrounding Marais district — also Paris’ main gay neighborhood — which has brought in growing numbers of tourists and a French breed of impeccably dressed, casual-chic shoppers attracted to its ornate, medieval streets spared from the industrial bulldozer that carved through most of Paris in the 1800s.

While the shift began in the 1980s, the Rue des Rosiers kept its cultural identity relatively intact — until recently.

Land values in the Marais skyrocketed and demand rose 30 percent in just a year or two, said Jean-Michel Sokol, real estate manager and municipal councilman for the district. That was due in part to a city-driven renovation project.

Costly mandatory upgrades were enough incentive for those close to retirement to sell or lease the family business.

As their range of kosher food choice narrows, most Jewish Parisian shoppers head elsewhere, further pushing remaining merchants such as Fortune Benchetrit to sell off her family’s 45-year-old Jewish grocery store on neighboring rue des Ecouffes.

The community has not dealt easily with the shift.

“They destroyed the oldest Jewish quarter in France in a matter of five years,” said Michel Kalifa, a kosher butcher and president of an association fighting to hold onto the area’s Jewishness.

However, others see the affair as a compromise.

“Social evolution is not a problem,” said the president of the Orthodox Jewish community, Daniel Altmann. “There are enough services to permit people who want to express their spiritual life to do so, and that’s the objective.”

A nucleus of Jews still makes the trip to the Marais to shop for Jewish holidays or make a grocery run. And the Orthodox community, though shrunken in size, maintains Jewish schools and serves 200 families from its synagogue in the neighborhood.

To those Jewish merchants who remained, Bertinotti recommended that they win back lost customers by improving the quality of their wares.

“We have to stop with this idea that the Jewish identity comes down to a few shops,” she added.

The mayor also said she hoped to install a Holocaust memorial library at Jo Goldenberg’s.

Locals such as Ernest Buchwald, vice president of the Paris Jewish Memorial Association, who has lived in the neighborhood for 70 years, said they understood why many were nostalgic for the charm of another era.

But not all have Buchwald’s memories of those humbler times, when the neighborhood’s poor families slept and worked in the same crammed room without heat and water.

“When we remember, we think of the good things, because we were young, but they forget — there was no comfort,” he said.

“It’s normal that we transform all this,” he said. “We can’t always stay in the Middle Ages.”

Leaning forward, he winked, and nodded toward the luxury clothing shops now entirely covering the western half of the street. “You know, the boutiques that are here, they’re Jews who run them,” he said.

As he spoke, Zapa, a luxury clothing store that opened seven months ago, was blasting a Hebrew pop song over the radio.