Synthese von (+)-Aspicilin mit Bausteinen aus nachwachsenden Rohstoffen

Synthesis of (+)-Aspicilin Using Building Blocks from Renewable Resources The 18-membered lichen macrolide (+)-aspicilin ( 1 ) is easily built up from compounds 14 , 16 , 3 , and 24 following the C₃ + C₇ + C₆ + C₂ = C₁₈ pattern (see Schemes). The synthesis requires 15 steps and gives 1 in 13% overall yield from D -mannose ( 2 ). The latter compound provides the stereogenic centers C(4), C(5), and C(6). The stereogenic center C(17) is supplied by building block 14 (from (?)-(S)-ethyl lactate).