Synthesis of the C11−C29 Fragment of Amphidinolide F

An efficient synthesis of the C(11)−C(29) fragment 31 of amphidinolide F has been accomplished via a diastereoselective [3 + 2]-annulation reaction of allylsilane 5 and ethyl glyoxylate to prepare the key tetrahydrofuran 15 and a highly stereoselective methyl ketone aldol reaction to generate the C(11)−C(16) segment.