Raman tag

1. A method of forming a probe, the method comprising:

converting cholenic acid into a compound with a terminal alkyne group, wherein the converting cholenic acid includes using a sequence, wherein the sequence includes synthesizing a THP-protection group, LiAlH4 reduction,

Dess-Martin oxidation, and Seyferth-Gilbert-Bestmann homologation, wherein the converting cholenic acid into the compound with the terminal alkyne group includes:

adding 3,4-dihydro-2H-pyran (DHP) and p-toluenesulfonic acid monohydrate (p-TsOH) to a mixture of cholenic acid and THF and extracting a first residue therefrom;

adding the first residue to a suspension of LiAlH4 in dry THF and extracting a second residue therefrom;

adding Dess-Martin Periodinane to a suspension of the second residue and NaHCO 3 and extracting a third residue therefrom;

adding dimethyl-1-diazo-2-oxopropylphosphonate to a solution of the third residue and K 2 CO 3 and extracting a fourth residue therefrom;

mixing the fourth residue, CuI, P(o-Tol) 3 , K 2 CO 3 , compound A, and anhydrous EtOH and extracting an eleventh residue therefrom, wherein the eleventh residue includes:

2. The method of claim 1 , wherein the first residue includes:

3. The method of claim 1 , wherein the second residue includes:

4. The method of claim 1 , wherein the third residue includes:

5. The method of claim 1 , wherein the fourth residue includes:

6. The method of claim 1 , wherein the compound A is

7. The method of claim 1 further comprising:

forming alkyne cholesterol (A-Chol) by removing the THP-protection group;

forming phenyl-alkyne cholesterol (PhA-Chol) from the compound with the terminal alkyne group via a palladiumcatalyzed Sonogashira reaction; and

forming phenyl-diyne cholesterol (PhDY-Chol) from the compound with the terminal alkyne group via a coppercatalyzed Cadiot-Chodkiewicz reaction.

8. The method of claim 1 , further comprising removing the THP-protection group via an acid.

9. The method of claim 1 further comprising:

adding methanesulfonyl chloride to a solution of the second residue and trimethylamine in CH 2 Cl 2 and extracting a fifth residue therefrom, wherein the fifth residue includes:

10. The method of claim 9 further comprising:

adding potassium cyanide to a solution, wherein the solution includes the fifth residue and DMSO, and extracting a sixth residue therefrom, wherein the sixth residue includes:

11. The method of claim 10 further comprising:

dissolving the sixth residue and p-toluenesulfonic acid monohydrate in THF and methanol and extracting a seventh residue therefrom, wherein the seventh residue includes:

12. The method of claim 1 further comprising:

dissolving the fourth residue and p-toluenesulfonic acid monohydrate in THF and methanol and extracting an eighth residue therefrom, wherein the eighth residue includes:

13. The method of claim 1 further comprising:

mixing the fourth residue with CuI, iodobenzene, and trimethylamine, and extracting a ninth residue therefrom, wherein the ninth residue includes:

14. The method of claim 13 further comprising:

dissolving the ninth residue and p-toluenesulfonic acid monohydrate in THF and methanol, and extracting a tenth residue therefrom, wherein the tenth residue includes:

15. The method of claim 1 further comprising:

mixing the fourth residue, PdCl 2 (PPh 3 ) 2 , CuI, compound B, and THF, wherein the compound B includes

and extracting a thirteenth residue therefrom, wherein the thirteenth residue includes:

16. The method of claim 15 further comprising:

dissolving the thirteenth residue and p-toluenesulfonic acid monohydrate in THF and methanol, and extracting a fourteenth residue therefrom, wherein the fourteenth residue includes:

17. A method of forming a probe, the method comprising:

converting cholenic acid into a compound with a terminal alkyne group, wherein the converting the cholenic acid includes using a sequence, wherein the sequence includes synthesizing a THP-protection group, LiAlH4 reduction,

Dess-Martin oxidation, and Seyferth-Gilbert-Bestmann homologation, wherein the converting the cholenic acid into the compound with the terminal alkyne group includes:

adding 3,4-dihydro-2H-pyran (DHP) and p-toluenesulfonic acid monohydrate (p-TsOH) to a mixture of the cholenic acid and THF and extracting a first residue therefrom;

adding the first residue to a suspension of LiAlH 4 in dry THF and extracting a second residue therefrom;

adding Dess-Martin Periodinane to a suspension of the second residue and NaHCO 3 and extracting a third residue therefrom;

adding dimethyl-1-diazo-2-oxopropylphosphonate to a solution of the third residue and K 2 CO 3 extracting a fourth residue therefrom;

mixing the fourth residue, CuI, P(o-Tol) 3 , K 2 CO 3 , compound A, and anhydrous EtOH and extracting an eleventh residue therefrom, wherein the compound A includes

18. The method of claim 17 , wherein the eleventh residue includes:

19. A method of forming a probe, the method comprising:

converting cholenic acid into a compound with a terminal alkyne group, wherein the converting the cholenic acid includes using a sequence, wherein the sequence includes synthesizing a THP-protection group, LiAlH4 reduction, Dess-Martin oxidation, and Seyferth-Gilbert-Bestmann homologation, wherein the converting cholenic acid into the compound with the terminal alkyne group includes forming a resultant residue including:

20. The method of claim 19 , wherein the converting the cholenic acid into the compound with the terminal alkyne group includes:

adding 3,4-dihydro-2H-pyran (DHP) and p-toluenesulfonic acid monohydrate (p-TsOH) to a mixture of the cholenic acid and THF and extracting a first residue therefrom;

adding the first residue to a suspension of LiAlH 4 in dry THF and extracting a second residue therefrom;

adding Dess-Martin Periodinane to a suspension of the second residue and NaHCO 3 and extracting a third residue therefrom;

adding dimethyl-1-diazo-2-oxopropylphosphonate to a solution of the third residue and K 2 CO 3 and extracting a fourth residue therefrom;

mixing the fourth residue, CuI, P(o-Tol) 3 , K 2 CO 3 , compound A, and anhydrous EtOH and extracting the resultant residue.