Egon Spengler Oswald Spengler and a classmate of Ramis at Senn High School, Egon Donsbach, a Hungarian refugee. Christopher Walken, John Lithgow, Christopher Lloyd and Jeff Goldblum were all considered for the role of Egon Spengler, before Ramis, who had gotten close to the character while writing him, felt compelled to play it himself. LaMarche stated that when he auditioned for the part of Spengler in "The Real Ghostbusters", he was asked not to do an impression of Ramis, which he ignored because impressions were one of his strengths as a performer, and there was no other way he could imagine properly
Pictet–Spengler reaction tetrahydroisoquinoline synthesis. Reaction conditions are generally harsher than the indole variant, and require refluxing conditions with strong acids like hydrochloric acid, trifluoroacetic acid or superacids. Instead of catalyzing the Pictet-Spengler cyclization with strong acid, one can acylate the iminium ion forming the intermediate "N"-acyliminium ion. The "N"-acyliminium ion is a very powerful electrophile and most aromatic ring systems will cyclize under mild conditions with good yields. Tadalafil is synthesized via the "N"-acyliminium Pictet–Spengler reaction. This reaction can also be catalyzed by AuCl and AgOTf. When the Pictet–Spengler reaction is performed with an aldehyde other than formaldehyde, a new chiral center