Partial Synthesis of Crassicauline A from Yunaconitine

Both Aconitum hemsleyanum and Aconitum geniculatun have abundant contents of yunaconitine (1). Yunaconitine (1) has similar skeleton to crassicauline A (3); the only difference between them is that 1 contains a α-hydroxyl group at C-3. Our team attempts to convert 1 into 3 because 3 owns pharmacological activity. There are two steps to achieve the transformation above: firstly, use dehydration reaction to transform yunaconitine (1) into dehydroyunaconitine (2); secondly, use hydrogen reduction to acquire crassicauline A (3). Compared with other methods, this one below is more suitable for production application and more concise; moreover, the cost is lower with higher yield.