Transformation of sclareol under ritter reaction conditions

Sclareol under the mild conditions of Ritter reaction is converted into N,N'-[(8R,13)-labdan-14(15)-ene-8,13-diyl]diacetamides stereoisomeric at the C-13 atom possessing the unrearranged skeleton of the initial diol. One of the minor reaction products is the N-[(8 alpha,13)-epoxylabdan-14-yl]acetamide whose formation requires the intermediate cyclization of the sclareol. Under more severe conditions and at the reversed order of the reagents addition the prevailing components of the reaction mixture are cyclized and rearranged N-[(8 alpha,14)-epoxy-16(13 -> 14)-abeo-labdan-13-yl]acetamides stereoisomeric at the C-13 atom, and minor compounds, (8 alpha,13)-epoxy-16(13 -> 14)-abeo-labdan-12(13)-ene and (8 alpha,14)-epoxy-16(13 -> 4)-abeo-labdan-12(13)-ene.