Two new carotenoids, sapotexanthin 5,6‐epoxide and sapotexanthin 5,8‐epoxide, have been isolated from the ripe fruits of red mamey (Pouteria sapota). Sapotexanthin 5,6‐epoxide was also prepared by partial synthesis via epoxidation of sapotexanthin, and the (5R,6S) and (5S,6R) stereoisomers were identified by high‐performance liquid chromatography–electronic circular dichroism (HPLC‐ECD) analysis. Spectroscopic data of the natural and semisynthetic derivatives obtained by acid‐catalyzed rearrangement of cryptocapsin 5,8‐epoxide stereoisomers were compared for structural elucidation.