Pelretin

Pelretin
Names
	IUPAC name 4-[(1E,3E,5E)-4-Methyl-6-(2,6,6-trimethyl-1-cyclohexen-1-yl)-1,3,5-hexatrien-1-yl]benzoic acid
Identifiers
CAS Number	91587-01-8;
3D model (JSmol)	Interactive image;
ChEMBL	ChEMBL39861 ;
ChemSpider	4940263;
KEGG	D05402 ;
PubChem CID	6435504;
UNII	H9MC68UEZ9 ;
CompTox Dashboard (EPA)	DTXSID101032023 ;
	InChI InChI=1S/C23H28O2/c1-17(10-15-21-18(2)8-6-16-23(21,3)4)7-5-9-19-11-13-20(14-12-19)22(24)25/h5,7,9-15H,6,8,16H2,1-4H3,(H,24,25)/b9-5+,15-10+,17-7+ Key: YRNAHKPMDMVFMV-GMICYETFSA-N; InChI=1/C23H28O2/c1-17(10-15-21-18(2)8-6-16-23(21,3)4)7-5-9-19-11-13-20(14-12-19)22(24)25/h5,7,9-15H,6,8,16H2,1-4H3,(H,24,25)/b9-5+,15-10+,17-7+ Key: YRNAHKPMDMVFMV-GMICYETFBM;
	SMILES CC1=C(C(CCC1)(C)C)/C=C/C(=C/C=C/c2ccc(cc2)C(=O)O)/C;
Properties
Chemical formula	C23H28O2
Molar mass	336.475 g·mol−1
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Pelretin is a synthetic retinoid. It was tested in the 1980s on animals in the hopes that it could be used to eliminate wrinkles.^[1]

Synthesis

The key reaction in the construction of this compound consists in Wittig reaction of the ylide from phosphonate 3 with the extended aldehyde 4 used in the synthesis of tretinoin itself. Reaction of para-bromomethylbenzoate (1) with triethylphosphite probably proceeds by initial displacement of halogen by phosphorus to give a transient intermediate charged species such as 2. Displacement by one of the ethyl groups on phosphorus by bromide ion from the frist displacement followed by bond reorganization leads to phophonate (3), and EtBr as a by-product. Reaction of the ylide from that product with aldehyde 4 affords the extended polyene. Saponification then yields pelretin.

References

^ Recer, Paul (11 December 1989). "Is Vitamin A Cream a New Wrinkle in Skin Care, or Just Soft Soap?". Los Angeles Times. Retrieved 20 December 2014.
^ Dawson, M. I.; Hobbs, P. D.; Derdzinski, K.; Chan, R. L. S.; Gruber, J.; Chao, W.; Smith, S.; Thies, R. W.; Schiff, L. J. (1984). "Conformationally restricted retinoids". Journal of Medicinal Chemistry. 27 (11): 1516. doi:10.1021/jm00377a022.

[1] Recer, Paul (11 December 1989). "Is Vitamin A Cream a New Wrinkle in Skin Care, or Just Soft Soap?". Los Angeles Times. Retrieved 20 December 2014.

[2] Dawson, M. I.; Hobbs, P. D.; Derdzinski, K.; Chan, R. L. S.; Gruber, J.; Chao, W.; Smith, S.; Thies, R. W.; Schiff, L. J. (1984). "Conformationally restricted retinoids". Journal of Medicinal Chemistry. 27 (11): 1516. doi:10.1021/jm00377a022.

[1]

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