Highly Efficient, Enantiocontrolled Total Syntheses of (+)-Heliannuol D and (–)-Helibisabonol A
摘要:
Enantiocontrolled total syntheses of (+)-heliannuol D (1) and (-)-helibisabonol A (2) have been accomplished efficiently from a common intermediate 9, derived from the optically pure aryl allyl ether 7 via a chirality transfer through a Lewis acid-mediated Claisen rearrangement and asymmetric dihydroxylation.
Highly Efficient, Enantiocontrolled Total Syntheses of (+)-Heliannuol D and (–)-Helibisabonol A
摘要:
Enantiocontrolled total syntheses of (+)-heliannuol D (1) and (-)-helibisabonol A (2) have been accomplished efficiently from a common intermediate 9, derived from the optically pure aryl allyl ether 7 via a chirality transfer through a Lewis acid-mediated Claisen rearrangement and asymmetric dihydroxylation.
An efficient totalsynthesis of (+)-heliannuol D was accomplished in 14 steps and in 12% overall yield by employing a diastereoselective conjugate addition reaction to create a tertiary benzylic stereogenic center and simple assembly of the functionalized oxepane framework by an efficient one-pot transformation procedure as the key steps.
The first enantiocontrolled total synthesis of heliespirone B has been accomplished employing a biomimetic intramolecular oxy-Michael reaction followed by the regio- and diastereoselective reduction of the carbonyl function as key steps. (C) 2012 Elsevier Ltd. All rights reserved.