Y-amino acid synthesis

Efforts to develop a y amino acid synthesis in which the oxidation state need not be adjusted after coupling led to the hypothesis that y hydrazonoesters may be com petent radical acceptors. Would the stereocontrol model be applicable in the presence of an additional Lewis basic ester function in the hydrazone. This question was addressed via prototypical Mn mediated photolytic conditions with InCla as the Lewis acid. Successful coupling was achieved between isopropyl iodide and a variety of y hydrazonoesters 52a S2d (Table 2.7, entries 1 4) bearing methyl, dimethyl, and benzyloxy substituents at the position (1 to the hydrazone (a to the ester). Consistently high diastereoselectivities and excellent yields (91 98%) of the isopropyl adducts S3a S3d indicated that the substitution patterns examined in this study had little effect on reaction selectivity and efficiency. 

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