877168-02-0Relevant articles and documents
Enantioselective Approach to the Right-Hand Substructure of Solanoeclepin A
Lutteke, Ginger,Kleinnijenhuis, Roel A.,Beuving, Remmelt J.,de Gelder, René,Smits, Jan M. M.,van Maarseveen, Jan H.,Hiemstra, Henk
, p. 5845 - 5854 (2016)
An enantioselective synthesis of the right-hand substructure of solanoeclepin A has been developed. The key step was an intramolecular [2+2] photocycloaddition between an allene and a butenolide providing a methylenecyclobutane with three quaternary carbon atoms in a complex tetracyclic framework. Other crucial steps included an enantioselective Noyori transfer hydrogenation of a ketone, a diastereoselective silver-mediated silyl dienolate allylation, and a diastereoselective cyclopropanation of an allylic alcohol. The installation of the bridgehead methyl group by reduction of the lactone moiety proved to be troublesome.
Indium-mediated allenylation of aldehydes and its application in carbohydrate chemistry: Efficient synthesis of D -ribulose and 1-deoxy- D -ribulose
Fischer, Michael,Schmoelzer, Christoph,Nowikow, Christina,Schmid, Walther
supporting information; experimental part, p. 1645 - 1651 (2011/05/05)
A two-step reaction sequence starting with the indium-mediated allenylation of aldehydes with 4-bromo-2-butyn-1-ols and subsequent ozonolysis of the resulting allenylic product was developed to generate a variety of dihydroxyacetone derivatives. The regioselectivity of the indium-promoted C-C bond-forming reaction can be manipulated through hydroxy protecting groups on 4-bromo-2-butyn-1-ol, yielding either allenes or alkynes as preferred products. Compared to established protocols, the necessary amount of indium for this type of allenylation can be decreased by a factor of two to four. The versatility of this strategy was demonstrated in thestereoselective and straightforward synthesis of D-ribulose and 1-deoxy-D-ribulose. Copyright
Synthesis of the tricyclic core of solanoeclepin A through intramolecular [2+2] photocycloaddition of an allene butenolide
Hue, B. T. Buu,Dijkink, Jan,Kuiper, Sanne,Van Schaik, Sjoerd,Van Maarseveen, Jan H.,Hiemstra, Henk
, p. 127 - 137 (2007/10/03)
Studies are reported towards the synthesis of solanoeclepin A (1), the hatching agent of potato cyst nematodes. Two approaches are investigated to access the tricyclic core including the intricate bicyclo[2.1.1]hexanone moiety. The first approach is based on the intramolecular [2+2] photocycloaddition of dioxenone butenolide 10 and is shown to be less practical due to the limited synthetic utility of the photoproduct 11. The second approach uses as the key step the intramolecular [2+2] photocycloaddition reaction of allene butenolide 39. This latter photosubstrate is prepared through silver-mediated coupling of silyloxyfuran 9 and allenic bromide 34. A five-step sequence starting with the Baylis-Hillman reaction between benzyl butadienolate and paraformaldehyde leads to bromide 34. The crucial photocycloaddition of 39 proceeds with excellent regioselectivity and produces the adduct 40 in good yield. This methylenecyclobutane-containing product 40 is deemed to contain the appropriate functionalities for future studies towards the natural product as is indicated through a model study leading to cyclobutanone 25. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
