An Enantioselective Total Synthesis of (+)-Ricciocarpin A

Abstract

[reaction: see text] Starting from 4,4-dimethyl-2-cyclohexenone, an efficient total synthesis of ricciocarpin A (1) in natural form has been accomplished.

Second-generation synthesis of salvinorin A

“…After numerous attempts employing magnesium in methanol, lithium naphthalenide, and catalytic hydrogenation, we finally found that the double reduction proceeded successfully with samarium diiodide. 11 Careful tuning of reaction conditions revealed that the freshly prepared samarium diiodide furnished lactonic ester 22 in the presence of triethylamine 12 as a ligand and acetic acid as a proton source in toluene in 64% yield as a single diastereomer. No other steroisomers were obtained.…”

Efficient microwave-assisted one-pot three-component synthesis of 2,3-disubstituted benzofurans under Sonogashira conditions

“…The following compounds were prepared following the procedure described in the literature: iodophenols 8 13 and 12 14 ; 3-iodo- N -tosylindole ( 49 ), 15 3-iodo-4 H -chromen-4-one ( 51 ), 16 2-iodo-4,4-dimethylcyclohexenone ( 63 ). 17 …”

Recent Development in Palladium-Mediated Synthesis of Oxygen Heterocycles

“…159 In the presence of PdCl 2 -CuCl 2 catalytic system and carbon monoxide optically Another interesting example of palladium-catalyzed cyclocarbonylation reaction was encountered during the synthesis of the lactone ring of (+)-Ricciocarpin A 1 279. 163 The lactone ring (+)-278 was constructed via intramolecular carbonyl insertion of the alcohol (-)-277 in the presence Pd(OAc) 2 and triphenylphosphine. Reduction of compound 278 with sodium borohydride resulted in the formation of (+)-ricciocarpin 279 (Scheme 89).…”