Improved Stereoselective Syntheses of （-t-）-Valiolamine and （-I-）-Valienamine Starting from （-）-Shikimic Acid

Improved stereoselective syntheses of the targeted compounds （＋）-valiolamine 1 and （＋）-valienamine 2 starting from naturally abundant （–）-shikimic acid are described. A common key intermediate compound 7 was first synthesized from （–）-shikimic acid in 9 steps. The compound 7 was then converted to （＋）-valiolamine 1 in 3 steps, and was also converted to （＋）-valienamine 2 in 4 steps. In summary, （＋）-valiolamine 1 and （＋）-valienamine 2 were synthesized from （–）-shikimic acid in 12 （or 13） steps in 40% and 39% overall yields, respectively.