LARGE-SCALE ISOLATION OF LOLITREM-B AND STRUCTURE DETERMINATION OF LOLITREM-E

A method for isolation of hundreds of milligrams of lolitrem B is repo rted. Lolitrem E, the most abundant of the minor lolitrems, was isolat ed from side fractions and its structure determined by mass spectromet ry and one- and two-dimensional NMR techniques. Lolitrem E differs fro m lolitrem B in being an ether, rather than an acetal, derivative of l olitriol. Evidence is presented that the compound previously isolated by Gallagher and co-workers, and assigned the structure of lolitrem C, was in fact lolitrem E. Lolitrem E, which is not tremorgenic in mice, is proposed as a biosynthetic precursor of lolitrem B.