When Michael Douglas met Diane Keaton

Director Rob Reiner, who memorably matched Billy Crystal and Meg Ryan for the classic romantic comedy “When Harry Met Sally,” is now making sexagenarian sparks with Michael Douglas and Diane Keaton with “And So It Goes.”

“They meshed perfectly,” Reiner says of his stars, who had never acted together previously. “The chemistry was there right off the bat.”

Douglas plays Oren Little, whose grumpy exterior is punctured by a romance with neighbor Leah (Keaton) and meeting a granddaughter named Sarah (Sterling Jerins) he didn’t know he had.

“Oren doesn’t turn into a mensch, he was that, but that’s covered over by what life has dealt him,” says Reiner.

Keaton suggested changing Leah from someone who made embroidered tapestries (which Reiner called “boring”) to a woman embarking on a new career as a singer.

“We live longer now than we ever have,” says Reiner. “We can have two or three careers in a lifetime.”

In terms of his own career, the human stories that were the 67-year-old filmmaker’s bread and butter are now “an endangered species for the studios.”

“I was looking at all these pictures I’ve done and not one of them could be made at a studio today, including ‘When Harry Met Sally.'”

After a career that spans acting in ’70s sitcom “All in the Family” to directing surprise hits “The Bucket List,” Reiner is hopeful that Baby Boomers will come out for “And So It Goes.”

“We’re still the largest segment of the population,” he insists. “We still love to go to movies and we don’t watch movies with electronic devices in our hands.”