N-Tosylglycine esters

In the absence of 7-hydrogen, other intramolecular hydrogen abstraction processes can become competitive. For example, a highly diastereoselective pho-tocyclization to cw-3-hydroxyproline derivatives is observed with substituted N-(2-benzoylethyl)-N-tosylglycine esters 155. The products 156-157 involve a 8-hydrogen abstraction by the excited carbonyl and a cyclization of the 1,5-biradical intermediate. In the presence of a (3-substituent, a high asymmetric induction is observed. The observed selectivity can be deduced from the preferred conforma-... [Pg.211]

Potassium tert-butanol Pyrrole-2-carboxylic acid esters from

pyrroline-carboxylic acid esters... [Pg.464]

N-Tosylglycine ethyl ester, 703 Tosyl hydrazide, see p-Toluenesulfonyl-hydrazide... [Pg.729]

Synthesis of pyrrales. A key step in a new synthesis of pyrroles is the base-catalyzed condensation of methyl vinyl ketone with an N4osyl amino acid ester, for example N-tosylglycine ethyl ester (1). Dehydration of the pyrrolidine (2)... [Pg.1085]

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