Catalytic asymmetric total synthesis of (+)-artalbic acid

Abstract

The first total synthesis of (+)-artalbic acid has been accomplished using asymmetric allylation of an acetoacetate derivative with a phase-transfer catalyst. This synthetic work was completed in 12 steps from isopropyl acetoacetate with high stereocontrol. In addition, the absolute configuration of naturally occurring artalbic acid was determined to be 7S, 9S, and 10S.

Ring contraction in synthesis of functionalized carbocycles

“…119 This was followed by boration with triethylborane 136 to generate a carbocation intermediate 137 , which underwent 1,2-carbon migration yielding product 138 . The successive oxidation of borane 138 with trimethylamine N -oxide and Dess–Martin periodinane afforded cyclopentane 139 in 69% yield (contractive synthesis: 5 steps; 118 alternative synthesis: 12 steps 120 ).…”

Asymmetric catalytic construction of fully substituted carbon stereocenters using acyclic α-branched β-ketocarbonyls: the “Methyl Rule” widely exists

“…This synthetic work was completed in 12 steps from isopropyl acetoacetate with high stereocontrol (Scheme 34). 39 In 2014, the Xiao group developed a new type of chiral sulfoxide-phosphine ligand by a rational combination of two privileged scaffolds for Pd-catalyzed asymmetric allylic alkylation reactions. Generally high yields and excellent enantioselectivities were obtained.…”