ATROPO-ENANTIOSELECTIVE SYNTHESIS OF A SIMPLIFIED ANALOG OF MASTIGOPHORENE-A AND MASTIGOPHORENE-B

A first approach to the atroposelective total synthesis of mastigophor enes is described, the directed preparation of a structurally slightly modified analog of mastigophorenes A and B, with a tert-butyl instead of a substituted, chiral cyclopentyl residue. Its (partially protecte d) monomeric half is dimerized by oxidative (phenolic) coupling to giv e the corresponding biphenyl in a racemic form, or atropo-enantioselec tively via the corresponding biaryl lactone, to give the M-or, optiona lly, the P-enantiomeric form, by stereoselective ring opening and subs equent standard transformations. (C) 1998 Elsevier Science Ltd. All ri ghts reserved.