Camphorsultam

Camphorsultam
Names
IUPAC name
2,10-Camphorsultam
Other names
Camphorsultam, Bornanesultam, Oppolzer's Sultam, (–)-10,2-Camphorsultam, (1S)-(–)-2,10-Camphorsultam, (1S,5R,7R)-10,10-Dimethyl-3-thia-4-azatricyclo[5.2.1.01,5]decane 3,3-dioxide, (3aS,6R,7aR)-8,8-Dimethylhexahydro-3a,6-methano-2,1-benzisothiazole 2,2-dioxide, (−)-exo-10,2-Bornanesultam
Identifiers
ChemSpider 628224
Jmol-3D images Image
PubChem 719751
Properties
Molecular formula
 C10H17NO2S
Molar mass 215.31 g·mol−1
Appearance White, crystalline solid
Density 1.287 g/cm3
Melting point 181 to 183 °C (358 to 361 °F; 454 to 456 K)
Boiling point 325 °C (617 °F; 598 K)
1.567
Hazards
Main hazards Irritating to respiratory system and respiratory tract
Flash point 105.3 °C (221.5 °F; 378.4 K)
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Camphorsultam, also known as bornanesultam, is a crystalline solid primarily used as a chiral auxiliary in the synthesis of other chemicals with a specific desired stereoselectivity. Camphorsultam is commercially available in both enantiomers of its exo forms: (1R)-(+)-2,10-camphorsultam and (1S)-(−)-2,10-camphorsultam.

Synthesis

Camphorsultam is synthesized by reduction of camphorsulfonylimine. This reaction was originally performed as a catalytic hydrogenation using Raney Nickel,[1] but the modern preparation instead uses lithium aluminium hydride for the reduction.[2] These reductive methods are stereoselective: although both the endo and exo diastereomeric forms are theoretically possible, only the exo isomer is actually produced due to steric effects of one of the methyl groups.[1] Camphorsultam is often referred to as Oppolzer's sultam in reference to Wolfgang Oppolzer and colleagues, who developed the lithium aluminium hydride approach to this compound and pioneered its use in asymmetric synthesis.[3][4]

Uses

Due to its ability to form derivatives through its nitrogen atom and the structural rigidity of its chirality, camphorsultam is often used in reactions as a chiral auxiliary in order to allow a reaction to proceed with very specific stereoselectivity. During the synthesis of Manzacidin B, camphorsultam is used in order to obtain the desired stereoselective product.[5] During a Michael reaction or a Claisen rearrangement, camphorsultam is able to confer a great deal of stereoselectivity. This allows for more control over the reactions and the creation of very specific desired products.[6][7]

Camphorsultam also has applications in determining a compound's absolute stereochemistry. For that reason, it is sometimes referred to as a "chiral probe".

References

  1. ↑ 1.0 1.1 Shriner, R. L.; Shotton, J. A.; Sutherland, H. (1938). "Anomalous Mutarotation of Salts of Reychler's Acid. VI. Synthesis and Structure of the Sultam of 2-(N-Methylamino)-d-camphane-10-sulfonic Acid". J. Am. Chem. Soc. 60 (11): 2794. doi:10.1021/ja01278a072.
  2. ↑ Weismiller, Michael C.; Towson, James C.; Davis, Franklin A. (1990). "(−)-D-2,10-Camphorsultam". Org. Synth. 69: 154.; Coll. Vol. 8, p. 110
  3. ↑ Oppolzer, Wolfgang."Camphor as a natural source of chirality in asymmetric synthesis".Pure & Appl. Chem.,Vol. 62, No. 7, pp. 1241-1250, (1990).
  4. ↑ http://www.columbia.edu/cu/chemistry/groups/synth-lit/cir/2007_07_27-Shengping-Oppolzer3.pdf
  5. ↑ Shinada, Tetsuro; Oe, Kentaro; Ohfune, Yasufumi (2012). "Efficient Total Synthesis of Manzacidin B". Tetrahedron Letters 53 (26): 3250–3253. doi:10.1016/j.tetlet.2012.04.042.
  6. ↑ Tsai, Wen Jiuan; Lin, Yi-Tsong; Uang, Biing-Jiun (1994). "Asymmetric Michael Addition of Thiols to (1R,2R,4R)-(–)-2,10-N-Enoylcamphorsultam". Tetrahedron 5 (7): 1195–1198. doi:10.1016/0957-4166(94)80155-X.
  7. ↑ Takao, Ken-ichi; Sakamoto, Shu; Touati, Marianne Ayaka; Kusakawa, Yusuke; Tadano, Kin-ichi (2012). "Asmmetric Construction of All-Carbon Quaternary Stereocenters by Chiral Auxiliary Mediated Claisen Rearrangement and Total Synthesis of (+)-Bakuchiol". Molecules 17 (11): 13330–13344. doi:10.3390/molecules171113330.