Total Synthesis of Aculeatins A and B, and Formal Synthesis of Aculeatin D and 6-epi-Aculeatin D through an Asymmetric Aldol Reaction

Abstract

A versatile and straightforward approach to the total synthesis of the dispirocyclic natural products aculeatins A, B, and D and 6-<i>epi</i>-aculeatin D was developed. The key steps involve a catalytic asymmetric aldol reaction using a titanium(IV) tetraisopropoxide/(<i>S</i>)-[1,1′-binaphthalene]-2,2′-diol system to form a C-2 hydroxy group, a hydroxy-directed­ reduction, and a Weinreb ketone synthesis.