著者

Shiina Isamu

出版者

The Chemical Society of Japan

雑誌

Bulletin of the Chemical Society of Japan (ISSN:00092673)

巻号頁・発行日

vol.87, no.2, pp.196-233, 2014

被引用文献数

40

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After initially establishing a novel cyclization reaction of ω-hydroxycarboxylic acids (seco-acids) using 4-trifluoromethylbenzoic anhydride (TFBA) and Lewis acid catalysts to form the corresponding lactones, we discovered a more advanced method for this transformation using 2-methyl-6-nitrobenzoic anhydride (MNBA) as a coupling reagent with nucleophilic catalysts. The latter lactonization is promoted by acyl-transfer catalysts, such as 4-(dimethylamino)pyridine (DMAP), 4-pyrrolidinylpyridine (PPY), and 4-(dimethylamino)pyridine <i>N</i>-oxide (DMAPO). (+)-Ricinelaidic acid lactone ((+)-<b>2</b>) was first synthesized by the TFBA-mediated cyclization with Lewis acid catalysts, while the <i>threo</i>-aleuritic acid lactone (<b>20</b>) was alternatively synthesized by the MNBA-mediated cyclization with acyl-transfer catalysts. Using this effective lactonization technology to form the ester linkage under mild conditions, we then demonstrated the preparation of various large-, medium-, and small-sized natural and unnatural lactones including (−)-cephalosporolide D ((−)-<b>3</b>), (−)-octalactin A ((−)-<b>4</b>), (−)-octalactin B ((−)-<b>25</b>), 2-epibotcinolide (<b>49</b>), (−)- and (+)-2-hydroxytetracosanolides ((−)-<b>77</b> and (+)-<b>77</b>), (−)- and (+)-2-hydroxy-24-oxooctacosanolides ((−)-<b>78</b> and (+)-<b>78</b>), (−)-tetrahydrolipstatin ((−)-THL, (−)-<b>117</b>), and the erythromycin A skeletons <b>103b</b>, <b>103c</b>, <b>104c</b>, and <b>105b</b>. The transition structures involved in the formation of the β-lactones from the corresponding 3-hydroxycarboxylic acids were then determined using DFT calculations at the B3LYP/6-31G*//B3LYP/6-31G* level, and the reactivity of several seco-acids was successfully predicted on the basis of the calculated thermodynamic properties of the transition structures.