Application of the Reaction of D-Glucose with Meldrum's Acid:Total Synthesis of the Styryl Lactones (+)-Goniofufurone and (+)-7-epi-Goniofufurone

摘要

The syntheses of the styryl lactones (+)-goniofufurone (1)and (+)-7 epi-goniofufurone (2) from D-glucose are presented. The key steps are the formation of the lactone moiety by reaction of the hemiacetals 15 and 16 with meldrum's acid (3) and the addition of phenylmagnesium bromide to the aldehydes 9 or 12. In the last case, we obtainedf the L-ido and D-gluco configurated products 13 and 14 in a 3:1 mixture. However,addition of ZnCl_2 shifted the diastereomeric ratio towards the desired compound 14.