Tetrahedron

Total synthesis of FK-506. Part 2: Completion of the synthesis

RE Ireland, L Liu, TD Roper, JL Gleason

Index: Ireland, Robert E.; Liu, Longbin; Roper, Thomas D.; Gleason, James L. Tetrahedron, 1997 , vol. 53, # 39 p. 13257 - 13284

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Citation Number: 29

Abstract

The C15 C16 bond of FK-506 was formed via sulfone anion coupling followed by chelation controlled reduction of the C15 ketone. Efficient methylation of the C15-OH was accomplished by a combination of Me3OBF4-4Å molecular sieves in the presence of Proton Sponge®. A procedure was developed to avoid epimerization at the C2 position of the pipecolinate section during alkaline hydrolysis. A reductive fragmentation of the C21–C24 ...