440643-10-7

Upstream product

• 214483-89-3 C₅₃H₈₈O₈Si₃ 
• 80522-42-5 triisopropylsilyl trifluoromethanesulfonate 
• 214483-91-7 (S,E)-1-(benzyloxy)hex-4-en-3-ol 
• 214483-90-6 (3S)-1-benzyloxy-4-hexyn-3-ol 
• 214483-92-8 (3S,4E)-3-methyl-7-benzyloxy-4-heptenoic acid ethyl ester 
• 214483-95-1 (S)-1-[(2S,3S,5S,7S,8S,9S)-8-Hydroxy-7-(2-hydroxy-ethyl)-3,9-dimethyl-1,6-dioxa-spiro[4.5]dec-2-yl]-propane-1,3-diol 
• 214483-93-9 (3E,5S,9S,10E)-5,9-dimethyl-1,13-bis(benzyloxy)-3,10-tridecadien-7-one 
• 214484-04-5 (5S,6E)-5-methyl-2-[(1R,2E)-1-methyl-5-(benzyloxy)-2-pentenyl]-3-oxo-9-(benzyloxy)-6-nonenoic acid ethyl ester 
• 440643-05-0 (3S,4S,5S,9S,10S,11S)-1,13-bis(benzyloxy)-5,9-dimethyl-3,4,10,11-tetrahydroxytridecane-7-one 
• 214484-06-7 C₁₆H₂₂O₆ 
• 214483-96-2 C₁₆H₂₄O₆ 
• 214483-97-3 C₁₉H₂₈O₆ 
• 214484-00-1 C₁₉H₃₀O₈ 
• 214484-08-9 C₂₄H₃₆O₈ 

Downstream Products

• 440643-02-7 C₅₄H₉₂O₉Si₃ 
• 440643-03-8 C₆₂H₁₀₀O₁₀Si₃ 

Relevant academic research and scientific papers

Halichondrin B: Synthesis of the C(37)-C(54) subunit

A synthesis of the C(37)-C(54) segment of the antimitotic polyether macrolide halichondrin B is described. β-Ketophosphonate 1, comprising rings L, M, and N of the natural product, contains the C(44) spiroketal, about which local C2 symmetry plays a key strategic role. Based upon recognition of this local C2 symmetry, a Claisen self-condensation of 4 led to the dienone 3b. Asymmetric bis(dihydroxylation) set the C(40), C(41), C(47), and C(48) stereocenters, and the resulting bicyclic spiroketal 8a was oxidized to tetracyclic bis(lactone) 2a. Alcohol 13 was isolated from the mono-functionalization of bis(lactone) 2a via a carbonyl methylenation/hydroboration protocol. Chelation-controlled allylation of the derived aldehyde, followed by diastereoselective iodocarbonate formation and hydrolysis established the C(51)-C(54) sidechain in 17a. Protection of the side-chain hydroxyl groups, and conversion of the remaining lactone to the corresponding β-ketophosphonate provided 1, a suitable coupling subunit (with a total of 10 asymmetric centers) for the total synthesis of halichondrin B. Overall, a 22 step synthetic route from known epoxide 5 produced 1 (4% overall yield), in its natural configuration.