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A Convergent Synthetic Route to (+)-Dynemicin A and Analogs of Wide Structural Variability

“…We speculated that alkali metal enolates derived from 55 underwent spontaneous decomposition, perhaps by transannular addition to the epoxide followed by Bergman cyclization of the ( Z )-enediyne group. After extensive experimentation, we found that carboxylation via a presumed magnesium enolate, using conditions first disclosed by Matsumura et al and extensively elaborated by Rathke et al., was highly effective when applied to the substrate 55 . Thus, treatment of the ketone 55 with magnesium bromide (2.5 equiv) and triethylamine (15 equiv) in acetonitrile at 23 °C under an atmosphere of carbon dioxide efficiently formed the vinylogous carbonic acid 57 in high yield, as determined by 1 H NMR analysis of the crude reaction mixture.…”

Asymmetric Hydrolysis of (±)-α-Substituted Garboxylic Acid Esters with Microorganisms

“…GC of the extract showed that 1 and 2 were in the ratio 6 : 4. The acid fraction gave (S)-2 (65 mg) having [Cl] Hydrolysis of methyl indan-l-carboxylate (9) with A .. sojae. A. sojae was cultured in Y-medium (lOOml) in a 500-ml Erlenmeyer flask for 4. days.…”

“…7 ) Methyl 2-phenylbutyrate and methyl Cl-(4-chlorophenyl)isovalerate were prepared from the corresponding arylacetonitriles by Clalkylation 8 ) followed by acid-hydrolysis and esterification. Methyl indan-I-carboxylate was obtained from indene and C02 9 ) followed by hydrogenation and esterification. Methyl 2-(6-methoxy-2-naphthyl)propionate was prepared from (S)-naproxen by esterifcation followed by racemization with NaOMe-MeOH, and methyl 2-(3-benzoylphenyl)propionate was synthesized from ketoprofen by esterification.…”