Methyl iodide → HCID 67927796, compound

HRID 1461464Notes

Reaction equation

HRID 1461464 reaction equation
[O:1]([C@@H:9]([C@H:11]1[C@@H:14]([S:15]([CH3:18])(=[O:17])=[O:16])[NH:13][C:12]1=[O:19])[CH3:10])[Si:2]([C:5]([CH3:8])([CH3:7])[CH3:6])([CH3:4])[CH3:3].[SnH4].[Si](Cl)(C(C)(C)C)(C)C.N12CCCC1=NCCC2.CI.CC(C)([O-])C.[K+]>C(Cl)Cl>[O:1]([C@@H:9]([CH:11]1[CH:14]([S:15]([CH3:18])(=[O:17])=[O:16])[NH:13][C:12]1=[O:19])[CH3:10])[Si:2]([C:5]([CH3:6])([CH3:7])[CH3:8])([CH3:4])[CH3:3]

Participants

8

Reactant 6

HCID 6328Methyl iodideHCID 28928tert-Butyldimethylsilyl chlorideHCID 763491,5-Diazabicyclo(4.3.0)non-5-eneHCID 123161StannaneHCID 14486197HCID 14486197, compound2×HCID 23665647Potassium tert-butoxide

Product 1

HCID 67927796HCID 67927796, compound

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

A multistep synthesis of (3R,4R)-3-[1(R)-(t-butyldimethylsiloxy)ethyl]-4-methylsulfonylazetidin-2-one (formula III, X=SO2CH3) from methyl (3S,5R,6S)-6-bromo-6[1(R)-hydroxyethyl]penicillanate is reported by Hirai et al., Tetrahedron Lett. 23, 4021 (1982). The synthesis involves tin hydride debromination of the starting material followed by protection of the hydroxy group of the 6-substituent by silylation with t-butyldimethylsilyl chloride and oxidation of the resulting product to the cis sulfone derivative. The crucial step of the synthesis, reported to be isomerization of the cis sulfone to the trans sulfone, was "satisfactorily" achieved by means of a catalytic amount of 1,5-diazabicyclo [4.3.0]non-5-ene (DBN) in methylene chloride at room temperature. Ring opening of the trans sulfone by treatment with excess methyl iodide and potassium t-butoxide afforded 3-[1(R)-(t-butyldimethylsiloxy)-ethyl]-4-methylsulfonylazetidin-2-one.

Workup

  1. customThe crucial step of the synthesis

Sources & evidence

ORD record
ord-0f49e7f003014014bc849478f7456c6b
Source dataset
uspto-grants-1991_12
Patent number
US05075439

Reaction notes

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