Synthetic routes to campesterol and dihydrobrassicasterol: a first reported synthesis of the key phytosterol dihydrobrassicasterol

Phytosterols are increasingly used as health supplements in functional foods and are associated with having both positive and negative effects on health. Given this disparity, an investigation of their full individual biological profile is imperative in order to assure food safety. This paper describes the de novo synthesis of pure phytosterols in multigram scale and we report the first synthesis of the key phytosterol dihydrobrassicasterol along with a comparison of routes to campesterol. A detailed spectroscopic analysis is included with full assignment of the 13C NMR spectroscopic data of both compounds, mixtures and their precursors leading to the potential use of NMR spectroscopy as a tool for analysis of these sterol mixtures.