Synthesis of 19‐Nor‐Vitamin D A‐Ring Synthons via Ring‐Closing Olefin Metathesis

Abstract

19‐Nor‐vitamin D A‐ring synthons were obtained from linear olefins by means of ring‐closing olefin metathesis followed by palladium‐catalyzed isomerization of the endocyclic olefin product to an exocyclic olefin.

Synthetic Chemical Probes That Dissect Vitamin D Activities

“…In our effort to delineate VD 3 activity, we initially searched for VD 3 analogs that activate VDR but lack SREBP inhibitory activity. An in-house library of 250 vitamin D congeners − was screened for their ability to inhibit the activity of an SREBP-responsive luciferase reporter, in which expression of luciferase is controlled by three SREBP binding sites. We found that a series of vitamin D analogs, bearing alkyltriazole and alkyltetrazole substituents at C2 ( 4 – 9 ) (Figure ), displayed limited SREBP inhibitory activities (Figure A).…”

The chemistry of the carbon-transition metal double and triple bond: Annual survey covering the year 2014

“…225) [592]; (10) cyclohexenes, including those employed in syntheses of fluorinated inositol analogs [593], fluorinated cyclohexenes [594], lundurine B (the enol ether was converted to the ketone without isolation) (e.g. 226) [595], sculponeatin N [596], vitamin D derivatives [597], ryanodol (e.g. [598], shikimic acids and pinitol [599], carbasugars [600], madangamine D ( a later step forms a macrocyclic amine via RCM) [601], the kaurene core [602], various securinega alkaloids [603], a labyssomicin C derivative (e.g.…”

Strategies for the Synthesis of 19-nor-Vitamin D Analogs

“…They chose (−)-quinic acid (18) as the starting material since it features the correct hydroxy stereochemistry and is commercially available. Nagasawa's group described [17] a new synthetic method to obtain A-ring synthons 28 (Scheme 5) based on ring-closing metathesis from a linear precursor, and then they applied it to synthesize 1α,25-(OH) 2 -19-nor-D 3 (3a). This strategy enabled the preparation of an A-ring with a more flexible substitution pattern.…”