A convenient, improved synthesis of (camphoryl)sulfonyl oxaziridines.

Mergelsberg, Ingrid; Gala, Dinesh; Scherer, Dominik; DiBenedetto, Donald J.; Tanner, Marcus

doi:10.1016/0040-4039(92)88039-8

Cited by 25 publications

(8 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The oxidation procedure comes from a thorough process optimization of the work published in 1992 by Schering Plough Research and Werthenstein Chemie AG . This is a very important feature of this process, as it lowers the global cost of goods associated with this chiral reagent.…”

Section: Resultsmentioning

confidence: 99%

Metal-Free Synthesis of the Methanol Solvate of (S)-Omeprazole Potassium Salt Using (1R)-(−)-10-Camphorsulfonyloxaziridine: Oxidation Process Development and Optical Purity Enhancement Strategy

Delsarte¹,

Santraine²,

Fours³

et al. 2018

Org. Process Res. Dev.

View full text Add to dashboard Cite

show abstract

Section: Resultsmentioning

confidence: 99%

Metal-Free Synthesis of the Methanol Solvate of (S)-Omeprazole Potassium Salt Using (1R)-(−)-10-Camphorsulfonyloxaziridine: Oxidation Process Development and Optical Purity Enhancement Strategy

Delsarte¹,

Santraine²,

Fours³

et al. 2018

Org. Process Res. Dev.

View full text Add to dashboard Cite

show abstract

“…Thus, the enantioselective enolate hydroxylation of 12 by oxaziridine 19 34 gave 15 in 58% yield with a 90:10 enantiomeric ratio (Scheme 3). 33 The tertiary alcohol group in 15 was protected with a benzyl group, and then, the Wittig olefination afforded alkene 16.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…ESI-HRMS were recorded with a Waters/Micromass LCT Classic time-of-flight mass spectrometer. Compounds 12 , 19 , and 26 , were prepared by following the reported procedures.…”

Section: Experimental Sectionmentioning

confidence: 99%

Studies toward the Total Synthesis of Nogalamycin: Construction of the Complete ABCDEF-Ring System via a Convergent Hauser Annulation

Peng

VanNieuwenhze

2018

J. Org. Chem.

View full text Add to dashboard Cite

The convergent synthesis of the complete ABCDEF-ring system within nogalamycin, an anthracycline natural product, was studied. The pivotal Hauser annulation for the anthraquinone core construction was achieved by the fusion of two highly functionalized segments: a cyanophthalide (the AB-ring segment) and a tricyclic quinone monoketal (the DEF-ring segment). Key transformations toward the AB-ring segment include an enantioselective enolate α-hydroxylation, a diastereoselective hydroborationoxidation, and a directed aromatic lithiation-formylation. To prepare the DEF-ring segment for annulation, a mild dearomatization of the F-ring phenol group by (diacetoxyiodo)benzene (PIDA) was employed.

show abstract

“…A well-known strategy for introduction of the hydroxyl group at an activated methylene position is based on reaction of oxaziridines with the corresponding enolate and 8,8-disubstituted derivatives such as the dichloro compound 16 , and these reagents are readily prepared in large quantities . We have found that several benzyl phosphonates (e.g., 17a − d ) undergo enantioselective hydroxylation upon treatment of the corresponding anions with nonracemic oxaziridines, giving the corresponding α-hydroxyphosphonates 18a − d in reasonable yields and ee's .…”

Section: Resultsmentioning

confidence: 99%

Synthesis of Nonracemic Dimethyl α-(Hydroxyfarnesyl)phosphonates via Oxidation of Dimethyl Farnesylphosphonate with (Camphorsulfonyl)oxaziridines

Cermak

Wiemer

1999

J. Org. Chem.

View full text Add to dashboard Cite

Several strategies for synthesis of nonracemic dimethyl α-(hydroxyfarnesyl)phosphonate and the parent phosphonic acid have been explored. Separation of diastereomeric derivatives prepared by esterification of racemic α-hydroxy phosphonate with (S)-(+)-O-methylmandelic acid was possible, and these diastereomers could be assigned absolute stereochemistry on the basis of literature precedent. However, hydrolysis to the α-hydroxy phosphonic acid was accompanied by extensive isomerization. Addition of a nonracemic phosphonamidite to farnesal also gave nonracemic material, but again hydrolysis was problematic. Oxidation of dimethyl farnesylphosphonate anion with nonracemic (camphorsulfonyl)oxaziridines was shown to be regio- and stereoselective for formation of the α-hydroxy phosphonate. Enantiomeric excess of ∼70% ee was established by conversion of the oxidation products to their (S)-(+)-O-methylmandelate derivatives. Although hydrolysis of these methyl esters was accompanied by extensive racemization, both enantiomers of α-(hydroxyfarnesyl)phosphonic acid were obtained in low ee by this strategy.

show abstract

A convenient, improved synthesis of (camphoryl)sulfonyl oxaziridines.

Cited by 25 publications

References 11 publications

Metal-Free Synthesis of the Methanol Solvate of (S)-Omeprazole Potassium Salt Using (1R)-(−)-10-Camphorsulfonyloxaziridine: Oxidation Process Development and Optical Purity Enhancement Strategy

Metal-Free Synthesis of the Methanol Solvate of (S)-Omeprazole Potassium Salt Using (1R)-(−)-10-Camphorsulfonyloxaziridine: Oxidation Process Development and Optical Purity Enhancement Strategy

Studies toward the Total Synthesis of Nogalamycin: Construction of the Complete ABCDEF-Ring System via a Convergent Hauser Annulation

Synthesis of Nonracemic Dimethyl α-(Hydroxyfarnesyl)phosphonates via Oxidation of Dimethyl Farnesylphosphonate with (Camphorsulfonyl)oxaziridines

Contact Info

Product

Resources

About