Synthesis of the beta-hydroxydopa-gamma-hydroxy-delta-sulfinylnorvaline component of ustiloxins A and B.

The dopa-sulfinylnorvaline component of ustiloxins A and B has been prepared using an Evans salen-Al-catalysed aldol reaction with a 6-mercaptoisovanillin derivative, followed by incorporation of the norvaline group and asymmetric oxidation of the resulting sulfide to give the corresponding sulfoxide.