Lactone; XIII.¹Phasentransfer-Oxidation nach Grignardierung: Eine einfache Synthese γ,γ-disubstituierter γ-Butyrolactone aus γ-Butyrolacton

Stereodivergent Synthesis of (+)- and (−)-Isolineatin

“…Next, exposure of 14 to an excess of methylmagnesium chloride in THF led to the addition of two methyl groups to the lactone and concurrent cleavage of the pivaloyl ester providing triol 16 in 84% yield (Scheme ) . Combination of methylmagnesium chloride with THF was critical for completing the conversion of 14 to triol 16 .…”

Solid-Supported tert-Alkoxycarbonylation Reagents for Anchoring of Amines during Solid Phase Organic Synthesis

“…We found that regiospecific monoalkylation of diols 2 by Merrifield resin is a simple, one-step approach to the synthesis of support bound tertiary alcohols that provides a range of carbon chain lengths between the linking functionality and the polymeric support (Scheme ). Thus, 6-methyl-1,6-heptanediol ( 2 , n = 5), 5-methyl-1,5-hexanediol ( 2 , n = 4), and 4-methyl-1,4-pentanediol ( 2 , n = 3) are prepared by the addition of excess MeLi to the appropriate lactone ( 1 , n = 5, 4, or 3), and 3-methyl-1,3-butanediol ( 2 , n = 2) is obtained commercially. Treatment of each diol with an equimolar amount of potassium tert -butoxide generates the corresponding monoalkoxides which are alkylated by Merrifield resin ( 3 ) to yield a series homologous solid-supported tert- alkyl alcohols ( 4 , n = 5, 4, 3, or 2).…”

N-Heterocyclic Carbene Catalyzed Reaction of Enals and 1,2-Dicarbonyl Compounds: Stereoselective Synthesis of Spiro γ-Butyrolactones

“…It is noteworthy that spirocyclic γ-butyrolactones are a structural motif in a number of natural products such as Pathylactone A and Napalilactone . In addition, they serve as key intermediates in the total synthesis of a variety of natural products . Consequently, there has been considerable interest in developing efficient synthetic methods for these compounds …”