Saturated analogs of poison ivy allergens. Synthesis of trans,trans- and cis,trans-3-alkyl-1,2-cyclohexanediols and sensitizing properties in allergic contact dermatitis
摘要:
Saturated analogues of poison ivy and oak allergens (3-alkylcatechols), i.e. trans,trans-3-alkyl-1,2-cyclohexanediols (alkyl = CH3, n-C5H11, n-C10H21, n-C15H31), have been prepared and used to sensitize guinea pigs. Only long-chain derivatives (carbon chain length greater than C10) are contact sensitizers. The sensitized animals cross-react to PDC (i.e. pentadecylcatechol, one of the allergens of poison ivy), but the converse is not true (PDC-sensitized animals do not react to cyclohexanediols). cis,trans-3-n-Pentadecyl-1,2-cyclohexanediol has also been synthesized and shown to be a sensitizer. There is not cross-reaction between trans,trans- and cis,trans-3-n-pentadecylcyclohexanediols, excluding a common skin metabolite.
Synthesis of carbonyl and dicarbonyl compounds from organometallic reagents and N-imidazolium-N-methyl amides and bis-amides
作者:María A. de las Heras、Juan J. Vaquero、JoséL. García Navio、Julio Alvarez-Builla
DOI:10.1016/0040-4020(96)00882-4
日期:1996.11
A new method for the synthesis of selective acylating agents is described from the reaction of carboxylic acids with 3-methyl-1-methylamino-3H-imidazol-1-ium salts in the presence of appropriate coupling reagents. The amides and bis-amides thus prepared reacted selectively with organometallics to afford ketones and diketones and with DIBALH to give aldehydes and dialdehydes in high yields.
Straightforward Synthesis of Sphinganines via a Serine-derived Weinreb Amide
作者:Regina C. So、Rachel Ndonye、Douglas P. Izmirian、Stewart K. Richardson、Robyn L. Guerrera、Amy R. Howell
DOI:10.1021/jo030355b
日期:2004.4.1
Sphinganines can be synthesized in just three steps from easily prepared serine-derived Weinreb amide 4. Pre-deprotonation of the acidic (N-H and O-H) protons of 4 allows for its efficient conversion to amino ketones 5. Such ketones can be selectively reduced to either erythro- or threo-sphinganines. Partially protected sphinganines 11 are also readily accessible in five steps from 4. Thus, Weinreb amide 4 represents one of the most versatile templates described to date for sphinganine synthesis.
Reaction of -benzoquinone bisacetals with organolithiums. A novel route to substituted veratroles