Enantioselective Organocatalytic Synthesis of α-Cyclopropylphosphonates through a Domino Michael Addition/Intramolecular Alkylation Reaction
作者:Ana Maria Faísca Phillips、Maria Teresa Barros
DOI:10.1002/ejoc.201301207
日期:2014.1
An organocatalytic dominoreaction consisting of Michael addition/intramolecular alkylation between α,β-unsaturated aldehydes and bromophosphonoacetates was developed. Highly functionalised cyclopropylphosphonates containing three chiral centres, one of them quaternary, were obtained with good diastereoselectivities of up to 83:17 and very high enantioselectivities of up to 99 %.
Intramolecular Allenolate Acylations in Studies toward a Synthesis of FR182877
作者:Christopher D. Vanderwal、David A. Vosburg、Erik J. Sorensen
DOI:10.1021/ol016994v
日期:2001.12.1
[GRAPHICS]During our efforts to synthesize the cytotoxic natural product FR182877, we discovered intramolecular reductive acylations that offer a stereocontrolled alternative to the classical Knoevenagel condensation for the formation of alpha -alkylidene beta -keto-delta -lactones. Other progress toward a synthesis of FR182877 includes a pi -allyl Stille coupling and a bromo Horner-Wadsworth-Emmons reaction that forms a 12-membered ring. Structural relationships among FR182877, hexacyclinic acid, macquarimicin A, and cochleamycin A are also discussed.