ChemInform Abstract: Lewis Acid-Catalysed Reactions of 2,2,2-Trichloroethyl 6-Diazopenicillanate and Imines: Rearrangements of Spiro-6-aziridine- and Spiro-6-oxiranepenicillanates. X-Ray Crystal Structures of (3S,6′S)-2,2,2-Trichloroethyl 3-(4-Nitrophenyl