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An asymmetric total synthesis of the proposed structure of (16Z,20E)-eushearilide, a novel 24-membered macrolide, was achieved via an enantioselective aldol reaction and 2-methyl-6-nitrobenzoic anhydride-mediated macrolactonization. The obtained synthetic compounds were not identical to the natural product. The newly proposed most likely structure of eushearilide, (±)-(16E,20E)-eushearilide, was determined on the basis of detailed NMR analysis, and (3R,16E,20E,23R)-(−)-eushearilide was successfully synthesized. A comparison of the optical rotation of (3R,16E,20E,23R)-(−)-eushearilide with that of the natural product confirmed that the true structure of naturally occurring eushearilide is the (3S,16E,20E,23S)-(+)-form.

A method for the synthesis of octalactin B is established via a new and quite effective mixed-anhydride lactonization for the synthesis of an eight-membered ring moiety using 2-methyl-6-nitrobenzoic anhydride with DMAP. Both an optically active linear precursor of the lactone and a side chain of octalactins are prepared by the enantioselective aldol reaction of ketene silyl acetals with aldehydes.

A new method for the synthesis of optically active anti-vic-hydroxymethyl units that correspond to anti-aldol derivatives is developed by way of successive enantioselective aldol and diastereoselective desulfurization reactions.