Tetrahedron

A synthetic strategy using Witkop's pyrroloindole for (−)-debromoflustramine B,(+)-ent-debromoflustramine B and (+)-ent-debromoflustramide B

…, MMB Marques, N Srinivasan, S Prabhakar, AM Lobo

Index: Cardoso, A. Sofia P.; Marques, M. Manuel B.; Srinivasan, Natarajan; Prabhakar, Sundaresan; Lobo, Ana M. Tetrahedron, 2007 , vol. 63, # 41 p. 10211 - 10225

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Citation Number: 25

Abstract

While prenylation of (−)-Witkop's pyrroloindole (2), secured from l-tryptophan under standard N-alkylation conditions, led to a ca. 1: 1 diastereoisomeric mixture of two C3a-alkylated indolenines 3 and 4, use of phase-transfer conditions altered this to ca. 1: 2. Reduction followed by N-prenylation of the resulting secondary amines gave C, N-dialkylated products. The derived separable diastereoisomeric (−)-and (+)-Barton esters 19a and 19b were ...