Little White Rose Films has tapped Dougray Scott to topline “Gang of One,” based on Gary Mulgrew’s memoir about his life in prison in the wake of the Enron scandal.The banner, headed by the husband-wife team of Tommy Gormley and Sarah Purser, has hired screenwriter Robert Murphy (“Rebus”) to adapt. Mulgrew is one of a trio of British businessmen — the NatWest three — indicted in 2002 on seven counts of wire fraud and then extradited from the United Kingdom to the United States in 2006. Each pleaded guilty to one count in exchange for the other charges being dropped. Mulgrew’s memoir, published by Hodder & Stoughton in the UK earlier this year, tells the story of Mulgrew’s rise from a Glasgow orphanage to his opulent life as a multi-millionaire banker in London to his eventual fall as a convict in a gang-infested prison in the middle of Texas. Gormley will make his directorial debut. His credits as a first assistant director include “Mission: Impossible — Ghost Protocol,” “Super 8,” and “Star Trek.” Scott, repped by WME, was seen most recently in “My Week with Marilyn.” Little White Rose is also developing “Confessions of a Justified Sinner” and “Weir of Hermiston,” based on the unfinished novel by Robert Louis Stevenson.