Reaction of the N-(α-chloroalkyloxycarbonyl)pyrrolidines 1 with lithium powder and a catalytic amount of 4,4′-di-tert-butylbiphenyl (DTBB, 2.5 mol-%) in the presence of different electrophiles [iBuCHO, tBuCHO, PhCHO, Et2CO, (CH2)5CO, PhCOMe, Ph2CO, Me3SiCl], in THF at temperatures ranging between –78 and –60°C leads, after hydrolysis with water, to the expected functionalized carbamates 2. Deprotection
Opportunities for insiders: A catalytic pinacol-type reductiverearrangement of 1,2-internal diols was developed by the use of a simple boron catalyst and two silanes (see scheme). The reaction occurs through a concerted, stereoinvertive mechanism and is applicable to several substrate scaffolds not usually amenable to pinacol-type reactions, such as aliphatic secondary–secondary diols, without the
3-diol (1) is transformed on copper catalysts into 4-methyl-4-hydroxyhexan-3-one (3) and 4-methylhexan-3-one (5), via 1,2-ethyl migration, this being the first experimental observation of 1,2-bondshiftisomerization on copper.
Phenyl-furan compounds as vitamin d receptor modulators
申请人:Gajewski Peter Robert
公开号:US20070105951A1
公开(公告)日:2007-05-10
The present invention relates to novel, non-secosteroidal, phenyl-furan compounds with vitamin D receptor (VDR) modulating activity that are less hypercalcemic than 1α,25dihydroxy vitamin D3. These compounds are useful for treating bone disease and psoriasis.
A two-component coating composition that includes (A) a first component containing an acid functional aliphatic polyester polyol having an acid number of at least 20 mg KOH/g and a hydroxyl number of from 50 to 500 mg KOH/g, and (B) a second component comprising one or more polyisocyanates can be used to direct-to-metal coat metal substrates by (i) mixing components (A) and (B) in the above-described composition to form a mixture; and (ii) applying the mixture to a surface of a metal substrate.