Synthesis of (±) Wine Lactone and Its Analogues by a Diels–Alder Approach

Abstract

A novel route to (Ϯ)-wine lactone (1) by a cis-selective kinetically controlled intramolecular Diels-Alder (IMDA) cycloaddition of the linear triene 2 is reported. The triene precursor was synthesised by TBAF-catalysed coupling of an acyl fluoride with an silyl enol ether. Four butadienyl but-3-enoates were prepared and cyclised under mild conditions to give a series of wine lactone analogues. The diastereoselectivity of the IMDA cycloadditions was determined by NMR spectroscopy and GC-MS, whereby the formation of the natural

Regioselective Copper-Catalyzed Carboxylation of Allylboronates with Carbon Dioxide

“…In this regard, C–C bond forming reactions represent a highly useful process. For example, direct carboxylation of strongly nucleophilic allylmetals such as organolithiums and Grignard reagents with CO 2 provides a straightforward method to prepare β,γ-unsaturated carboxylic acids, highly versatile building blocks incorporating two modifiable functional groups (Scheme a). − A major drawback of these reactions, however, is the high reactivity of the metal–carbon bond, which is incompatible with a number of sensitive functional groups.…”

Studies toward the Synthesis of Maoecrystal V

“…Alkylation of sesamol with hindered neopentylic alcohol 7 7 was carried out under the Mitsunobu conditions in 63% yield (Scheme 2). 8 ortho -Metalation of 8 with n -butyl-lithium in THF at room temperature followed by transmetalation with zinc chloride to the corresposnding arylzinc chloride reagent and coupling with methyl chloroxoacetate delivered ketoester 9 in 46% yield along with the recovery of 25% of the starting material.…”

“…Alkylation of sesamol with hindered neopentylic alcohol 7 was carried out under the Mitsunobu conditions in 63% yield (Scheme ) .…”