Stereoselective Synthesis of (+)‐Goniodiol, (+)‐Goniotriol, (–)‐Goniofupyrone, and (+)‐Altholactone Using a Catalytic Asymmetric Hetero‐Diels–Alder/Allylboration Approach

Abstract

The stereoselective total synthesis of several members of the styryllactone family was achieved efficiently from common intermediate 8, prepared by a catalytic asymmetric inverseelectron-demand hetero-Diels-Alder/allylboration sequence. The transformation of 8 into α,β-unsaturated lactone led to the preparation of (+)-goniodiol (1) in a reduced number of steps. The epoxidation reaction was used to generate the re-[a] Sciences Chimiques de Rennes, Ingéniérie Chimique et Molécules pour le Vivant,

Changes on enantioselectivity of a genetically modified thermophilic lipase by site-directed oriented immobilization

“…The catalytic properties of these new biocatalysts were evaluated in two different biotransformations: (i) the hydrolytic kinetic resolution of rac-2-O-butyryl-2-phenylacetic acid (rac-1) to produce (R)-mandelic acid (2), (ii) the desymmetrization of phenylglutaric acid dimethyl diester (3) to produce (S)-monomethylphenylglutaric acid (4) (Scheme 1) [20].…”

The Asymmetric Hetero‐Diels–Alder Reaction in the Syntheses of Biologically Relevant Compounds

“…Another example of an oxa-Diels-Alder reaction catalyzed by a chromium(III) catalyst was reported by Carboni et al [12] An inverse-electron-demand HDA reaction between the oxadiene 7 and vinyl ether 8 as the dienophile proceeded smoothly and set the stereochemistry at an early stage of the synthesis (Scheme 2). The HDA reaction yielded the allylborane 9 which reacted with the aldehyde 10 to provide a common building block (11), which in a few steps gave access to (+)-gonotriol (12), (+)-gonodiol (13), (+)-altholactone (14), and (À)-gonifupyrone (15).…”

Boron-substituted 1,3-dienes and heterodienes as key elements in multicomponent processes

“…Thereafter, several members of the natural styryllactone family 21 – 25 , displaying cytotoxic and antitumor activities, have been also prepared according to this methodology [62–64]. The combination of the catalytic hetero-Diels–Alder/allyboration sequence with a ruthenium-catalyzed isomerization gave access to the 6,8-dioxabicyclo[3.2.1]octane skeleton of (+)-iso- exo -brevicomin ( 26 , Scheme 18) [65].…”