A new methodology has been developed for the P-C bond cleavage of beta-carbonyl phosphonates. The alpha,alpha-disubstituted beta-keto phosphonates and the alpha-carbamoyl phosphonates have been shown to undergo dephosphonylation by reaction of their lithium enolate with LiAlH4, followed by quenching with aqueous H2SO4, affording regioselectively alpha,alpha-disubstituted ketone and alpha-substituted and alpha,alpha-disubstituted secondary amides.
INHIBITORS OF 15-HYDROXYPROSTAGLANDIN DEHYDROGENASE FOR STIMULATING PIGMENTATION OF THE SKIN OR SKIN APPENDAGES
申请人:MICHELET JEAN-FRANCOIS
公开号:US20110014250A1
公开(公告)日:2011-01-20
Inhibitors of 15-hydroxyprostaglandin dehydrogenase (15-PGDH), for example tetrazole, styrylpyrazole, phenylfuran, phenylthiophene, phenylpyrrazole, pyrazolecarboxamide, 2-thioacetamide and azo compounds, are useful for promoting or stimulating pigmentation of the skin and/or skin appendages and/or for preventing and/or for limiting depigmentation and/or whitening of the skin and/or skin appendages, notably for preventing and/or limiting canities.