Studies towards the total synthesis of narbonolide: stereoselective preparation of the C1-C10 fragment

An efficient stereoselective synthesis of the C1-C10 fragment of narbonolide is reported. The stereocentres at C2, 3, 4, 5, 8 and 9 in fragment 5 can be generated via an iterative asymmetric acyl-thiazolidinethione aldol reaction, whereas the stereocentre at C6 is installed by means of Myers alkylation.