Determination by Asymmetric Total Synthesis of the Absolute Configuration of Lucilactaene, a Cell‐Cycle Inhibitor in p53‐Transfected Cancer Cells

Abstract

A biomimetic pathway to lucilactaene (1) from NG‐391 has been developed which involves stereoselective reactions under very mild conditions. It was demonstrated that 1 racemizes rapidly, and the conditions under which racemization occurs were elucidated. Lucilactaene (1) isolated under neutral conditions is racemic, which suggests that either the natural product is racemized rapidly in the mycelia, or racemic 1 is biosynthesized.

Recent Advances in Boron‐Substituted 1,3‐Dienes Chemistry: Synthesis and Application

“…Aromatic dialdehydes react with diboronate‐butadienes forming three new stereocenters with usually high diastereoselectivity in 1,4‐naphthalene‐diols. The final products 434 are an important motif in natural compounds and have been used as intermediates in the biosynthesis of kinamycine derivatives such as luisols A and B or dihydroaltersolanol A …”

Antimalarials and Phytotoxins from Botryosphaeria dothidea Identified from a Seed of Diseased Torreya taxifolia

“…It is very likely that compound 5 is the precursor of both 3 and 4. The stereocenter at C-15 undergoes racemization (or epimerization) easily through ring opening, even under mild conditions [33,36]. The formation of methyl or glycerol ethers stabilizes this compound [36], but it is very likely that the product would be racemic in the case of 3 and diastereomeric in the case of 6.…”

“…The formation of methyl or glycerol ethers stabilizes this compound [36], but it is very likely that the product would be racemic in the case of 3 and diastereomeric in the case of 6. In the chemical synthesis of lucilactaene, the Michael addition occurs spontaneously between the hydroxy group of the hydroxyethyl moiety and  13(14) olefinic bond [36]. The glycerol moiety in 6 also has a stereogenic center, and a similar Michael addition with the primary hydroxyl group of the glycerol would create additional stereogenic centers, yielding diastereomers.…”

“…The stereocenter at C-15 undergoes racemization (or epimerization) easily through ring opening, even under mild conditions [33,36]. The formation of methyl or glycerol ethers stabilizes this compound [36], but it is very likely that the product would be racemic in the case of 3 and diastereomeric in the case of 6. In the chemical synthesis of lucilactaene, the Michael addition occurs spontaneously between the hydroxy group of the hydroxyethyl moiety and ∆ 13(14) olefinic bond [36].…”

Rapid Access to 3‐Acyl‐5‐alkoxybutyrolactams Using Triplet and Singlet Oxygen

“…While the 5‐hydroxy‐butyrolactam unit dominates in the family of natural tetramic and non‐tetramic γ‐lactams, its less fragile 3‐acyl‐5‐alkoxy counterpart of type A (Figure ) can be found in many natural and unnatural products which have interesting biological activities . Furthermore, these easy‐to‐handle compounds are useful precursors for the synthesis of a wide variety of other naturally occurring counterparts …”