media but are largely unfounded. Synthesis By the salamander Habermehl and Haaf have investigated the biosynthesis of samandarin with in vivo and in vitro experiments. Samandarin is synthesized from cholesterol precursors in the liver, testes, or ovaries. They found that the enlargement of ring A occurs by nitrogen insertion from a glutamine residue. The degradation of the carbon chain and hydroxylation of ring D is shown through the intermediates in the scheme below. The carbon chain on the D ring of cholesterol is degraded by functionalizations with carboxyl groups and sequential decarboxylation reactions. A hydroxyl group is also installed on the adjacent carbon to yield samandarin. These steps are performed by enzymes in the salamander. The details of the biosynthesis have not been elucidated completely. In the lab The chemical synthesis of samandarin was of interest by a few groups in the 1960s and 1970s but has not been pursued in recent years. The construction of ring A was of greatest synthetic interest. Shimizu in 1976 was able to successfully construct the bridged oxazolidone system with correct stereoselectivity. The steps proceeded with low to moderate yields. The last few steps of the synthesis is shown below. Using m-chloroperobenzoic acid, an epoxide is created onto the alkene. The addition of sodium azide will facilitate the anti-Markovnikov opening of the epoxide. Reduction with sodium borohydride completes the azaheterocycle and bridged oxazolidone through either a cyclic amidine intermediate or imino ester intermediate. See also Samandaridine References Cyclopentanes Neurotoxins Secondary alcohols Steroidal alkaloids Vertebrate toxins Salamanders Slovenian distilled drinks