Organic Chemistry is recognized as a course that presents many difficulties and conceptual challenges for students. To combat the high failure rates and poor student attitudes associated with this challenging course, we implemented a "flipped" model for the first-semester, large-enrollment, Organic Chemistry course. In this flipped course, lectures were replaced by short videos, which were delivered via a course management system, and class time was reserved for problem solving and other active learning activities. We assessed the impact of the flipped course on course grades and failure rate compared to historical course data. The results showed that there was a statistically significant improvement in A and B grades and a decrease in failure/withdrawal rates for the flipped course. We also assessed students' attitudes toward the course using a valid and reliable instrument, the Attitude toward the Subject of Chemistry Inventory Version 2 (ASCIv2). The results showed a statistically significant increase in students' emotional satisfaction and intellectual accessibility for the flipped course compared to those for traditional lecture courses. The flipped format of the course provided students with increased access to course material, which increased time for in-class group learning and discussion. We believe that this aspect of the course format led to a reduction in cognitive load, thereby increasing students' emotional satisfaction and intellectual accessibility in the course. Our results demonstrate that the flipped course model can be adopted for challenging, large-enrollment courses.