Whole Foods, which has been under pressure to turn its business around, named five new directors to its board. The organic grocer took this step in an effort to show it was open to changing its approach to business. The company’s sales and stock price have taken a hit, prompting two large shareholders — Jana Partners and Neuberger Berman — to call for Whole Foods to take action or explore a sale of the company. Whole Foods also announced that Keith Manbeck, a former executive with Kohl’s, has been hired as its new chief financial officer.