The influence of a 15-hydroxy group on the rearrangement reactions of steviol and its 16,17-epoxide
Abstract
A 15-hydroxy group prevents the steviol/isosteviol rearrangement taking place. In the presence of hydrobromic acid, the 15α-alcohol undergoes rearrangement to a 17-alcohol whilst the 15β-alcohol gives the 15-ketones. Treatment of a 15α-hydroxy-16,17-epoxide gives the 15α,16α-dihydroxy-17-bromide, the structure of which was confirmed by X-ray analysis.