Unsaturated sultones with normal, medium and large ring sizes were efficiently synthesized by ring closing metathesis of sulfonates. The required substrates were readily derived from alkenols and olefinic sulfonyl chlorides.
synthesized by ring closing metathesis (RCM) of sulfonates. The resulting α,β-unsaturated sultones act as dienophiles in intermolecular Diels-Alder reactions. A first cyclic sulfate formation throughRCM has been discovered, and a rapid access to p-lactams fused to a sultam moiety of variable ring size was developed from inexpensive, commercially available starting materials using RCM as the key operation
Enantioselective Template-Directed [2+2] Photocycloadditions of Isoquinolones: Scope, Mechanism and Synthetic Applications
作者:Susannah C. Coote、Alexander Pöthig、Thorsten Bach
DOI:10.1002/chem.201500173
日期:2015.4.27
enantioselective [2+2] photocycloaddition of isoquinolones with alkenes is presented, in which the formation of a supramolecular complex between a chiral template and the substrate ensures high enantioface differentiation by shielding one face of the substrate. Fifteen different electron‐deficient alkenes and ten different substituted isoquinolones undergo efficient photocycloaddition, yielding the cyclobutane
Reactivity of unsaturated sultones synthesized from unsaturated alcohols by ring-closing metathesis. Application to the racemic synthesis of the originally proposed structure of mycothiazole
作者:Alexandre Le Flohic、Christophe Meyer、Janine Cossy
DOI:10.1016/j.tet.2006.07.010
日期:2006.9
Unsaturated sultones have been synthesized from various primary or secondary alkenols by ring-closing metathesis of the corresponding unsaturated sulfonates. By treatment with a strong base, beta,gamma-unsaturated sultones can be metalated and subsequently alkylated with electrophiles. When iodomethylmagnesium chloride was selected as the electrophile, seven-membered ring beta,gamma-unsaturated sultones were converted into homoallylic conjugated (Z)-dienols. This methodology was applied to the racemic synthesis of the originally proposed structure of the marine natural product mycothiazole. (c) 2006 Elsevier Ltd. All rights reserved.