Frank McClelland, executive chef/owner of L'Espalier, confirmed that his restaurant will move from its location on Gloucester St. to Boylston St. within the new Mandarin Oriental Boston Hotel & Residences on September 15th. The Back Bay landmark will close its doors with a final dinner at 30 Gloucester St. on August 30th. L'Espalier's sister restaurant, Sel de la Terre, will also open its third restaurant at the Mandarin September 15th.