Stereoselective synthesis of (-)-centrolobine, an anti-Leishmania agent, was accomplished via an intramolecular Barbier-type reaction of iodo-ester with n- or t-butyllithium followed by Lewis acid-promoted Et3SiH reduction of the resulting hemiacetal. (C) 2008 Elsevier Ltd. All rights reserved.
Cyclic ethers have been effectively synthesized via the intramolecular cyclization of diols using trimethyl phosphate and NaH. The present cyclization could proceed at room temperature to produce 5–7 membered cyclic ethers in good to excellent yields. Substrates possessing a chiral secondary hydroxy group were transformed into the corresponding chiral cyclic ethers along with the retention of their
Stereoselective synthesis of (-)-centrolobine, an anti-Leishmania agent, was accomplished via an intramolecular Barbier-type reaction of iodo-ester with n- or t-butyllithium followed by Lewis acid-promoted Et3SiH reduction of the resulting hemiacetal. (C) 2008 Elsevier Ltd. All rights reserved.