This disclosure relates to substituted bicyclolactam, specifically pyrimido[5,4-f][1,4]oxazepin-5-one compounds of formula I where R1 is a bicyclic ring system and the other substituents are as given in the description, which are inhibitors of acyl coenzymeA: diacylglycerol acyltransferase 1 (DGAT-1), to pharmaceutical compositions containing them, to processes for their preparation, and to their use in therapy for the prevention or treatment of diseases related to DGAT-1 dysfunction or where modulation of DGAT-1 activity may have therapeutic benefit including but not limited to obesity, obesity related disorders, hypertriglyceridemia, hyperlipoproteinemia, chylomicronemia, dyslipidemia, non-alcoholic steatohepatitis, diabetes, insulin resistance, metabolic syndrome, hepatitis C virus infection and acne or other skin disorders.
