부산대학교 도서관

A general modular approach to members of the pederin family of antitumour agents, exemplified by syntheses of pederin (1.1), mycalamide B (1.5) and analogues (17-epi-1.5, 2.8, 2.9 and 2.10), is described. The common strategy makes use of a metallated dihydropyran approach to couple two advanced fragments. All 6 compounds are prepared from 6-lithio-2,3-dimethyl-4-phenylselenomethyl-3,4-dihydro-2H-pyran 1.59 and 2-(3- chloropropyl)-3,3-dimethyl-3,4-dihydro-2H-pyran-4-one 2.4. The key steps in the synthesis of pederin 1.1 or its analogues are Sharpless asymmetric dihydroxylations and a rhodium-catalysed directed reduction of an acylimidate. The key steps in the synthesis of the right fragment of mycalamide B 1.5 are a P2O5-mediated formation of the trioxadecalin ring, a Meerwein-Pondorf-Verley reduction to install the C13-stereogenic centre, installation of the C10-N bond in good yield and total stereocontrol at the C10 centre via a Curtius rearrangement and/or a Hofmann rearrangement, as well as Sharpless asymmetric dihydroxylations.