Diastereo‐ and enantioselective synthesis of the 18‐membered lichen macrolide (+)‐aspicilin

The asymmetric synthesis of the lichen macrolide (+)‐aspicilin ( 1 ) was realised in 19 steps and with high stereoselectivity (de ≥ 91 %, ee ≥ 96%). Three of the four stereogenic centres were generated by employing the SAMP/RAMP hydrazone method. Key steps of the synthesis are the α,α′‐double alkylation of RAMP hydrazone ( R )‐ 10 of 2,2‐dimethyl‐1,3‐dioxan‐5‐one B and the enantioselective synthesis of the bromo alcohol ( S )‐ 9 (subunit A ) by a combination of SAMP hydrazone α‐alkylation with subsequent Baeyer‐Villiger oxidation.