Towards stereochemical control: A short formal enantioselective total synthesis of pumiliotoxins 251D and 237A

• Jie Zhang,
• Hong-Kui Zhang and
• Pei-Qiang Huang

Beilstein J. Org. Chem. 2013, 9, 2358–2366, doi:10.3762/bjoc.9.271

• consisting of ozonolysis and reductive dehydroxylation provided the indolizidine derivative 5, which completed the formal enantioselective total synthesis of pumiliotoxins 251D and 237A. Keywords: enantioselective synthesis; Grignard reagent; pumiliotoxin 237A; pumiliotoxin 251D; reductive dehydroxylation

• ; ring closure; trans-methylation; Introduction Pumiliotoxins (PTXs, 1, Figure 1) such as pumiliotoxin 251D (2) are a subclass of indolizidine alkaloids isolated from the skin secretion of neotropical frogs. A total of 19 members have been isolated and partially characterized [1]. Pumiliotoxins are

• organic chemists, and numerous approaches have been reported [7][8][9]. Pumiliotoxin 251D (PTX 251D) (2) is the first structurally defined member of pumiliotoxins, a class of dendrobatid alkaloids isolated from Ecuadorean poisonous frog, Dendrobares tricolor in 1980 [10]. Since the pioneering work of