jo0520137_si_001.pdf (533.89 kB)
New Enantioselective Entry to Cycloheptane Amino Acid Polyols
journal contribution
posted on 2006-01-06, 00:00 authored by Claudio Curti, Franca Zanardi, Lucia Battistini, Andrea Sartori, Gloria Rassu, Luciana Auzzas, Annamaria Roggio, Luigi Pinna, Giovanni CasiraghiA diversity-oriented protocol has been developed for the assembly of densely hydroxylated cycloheptane
amino acids via succession of a vinylogous Mukaiyama aldol reaction (VMAR), a Morita−Baylis−Hillman reaction (MBHR), and an intramolecular pinacol coupling reaction (IPCR). The plan utilizes d-
or l-configured glyceraldehyde derivatives as “chiral” surrogates of glyoxal and N-[(tert-butoxycarbonyl)-2-(tert-butyldimethylsilyl)oxy]pyrrole as the synthetic equivalent of the α,γ-dianion of γ-aminobutanoic
acid. The parallel, asymmetric syntheses of four cycloheptane representatives proceed with high
diastereocontrol and virtually complete enantioselectivity in ten steps and overall yields of 15−37%.