Egon Spengler It is implied in one episode of the animated series that Spengler accidentally burned down his family's garage. Spengler is the only original Ghostbuster to return for the "Extreme Ghostbusters" series as a regular, acting as a mentor to the new Ghostbusters (the others appeared for a two-part episode, "Back in the Saddle"), and monitoring and sustaining the Containment Unit while working as a paranormal studies professor at a university. He is the de facto leader of the new, younger team of Ghostbusters; although the old team had gone into retirement after they apparently dealt with all the ghosts in
Pictet–Spengler reaction is created. Several substrate- or auxiliary-controlled diastereoselective Pictet–Spengler reactions have been developed. Additionally, List "et al." have published a chiral Brønsted acid that catalyzes asymmetric Pictet–Spengler reactions. Tryptophans: diastereocontrolled reaction The reaction of enantiopure tryptophan or its short-chain alkylesters leads to 1,2,3,4-tetrahydro-"β"-carbolines in which a new chiral center at C-1 adopts either a "cis" or "trans" configuration towards the C-3 carboxyl group. The "cis" conduction is kinetically controlled, i.e. it is performed at lower temperatures. At higher temperatures the reaction becomes reversible and usually favours racemisation. 1,3-"trans" dominated products can be obtained with "N"-benzylated tryptophans, which are accessible by reductive