Efficient Synthesis of 2—Ethyl—A—ring Analogues of 19—Nor—1α,25—dihydroxy Vitamin D3

The novel 19-nor-1α,25-dihydroxy vitamin D3 analogues possessing an ethyl at the 2-position(4 and 5).were synthesized by coupling 25-hydroxy Windaus-Grundmann ketone derivative 20 with A-ring synthons(15 and 19)respectively.The enantioselective synthesis of substituted bicyclic[3,1,0]hexanes structure A-ring synthons,started from all-cis-3,5-dihydroxy-4-ethyl-1-(methoxycarbonyl)cyclohexane via lipase-catalyzd asymmetrization,was demonstratcd.     

The synthesis of hexahydro-6H-dibenzo[b,d]pyrans: Derivatives of 9-Nor-9β-hydroxyhexahydrocannabinol

To assess the importance of the phenol functionality in cannabinoids for analgetic activity a new series of 9-nor-9β-hydroxyhexahydrocannabinoids was prepared. The synthesis of 1-substituted (H, CH₂OH, OH, NH₂) 6aβ,7,8,9,10,10aα-hexahydro-9β-hydroxy-6,6-dimethyl-3-[1-methyl-4-phenylbutoxy]-6H-dibenzo[b,d]pyrans from 3,5-dihydroxystilbene, 3,3′,5,5′-tetrahydroxystilbene or 1,3,5-trihydroxybenzene is described. Relative stereochemistry and structure confirmations were obtained by nmr and X-ray crystal analysis.     

9, 10-Secocholesta-(5Z)-5,8(14), 10(19)-trien-3β-ol und 18-Nor-14β-methyl-9,10-secocholesta-(5E)-5, 10(19), 13(17)-trien-3β-ol,zwei neue Doppelbindungsisomere des Vitamins D3. Strukturelle Abwandlungen am Vitamin D3: 5. Mitteilung [1]

9,10-Secocholesta-(5 Z )-5,8(14),10(19)-triene-3β-ol and 18-Nor-14β-methyl-9,10-secocholesta-(5 E )-5,10(19), 13(17)-trien-3β-ol, two new double bond isomers of vitamin D₃ . Structural modifications of vitamin D₃: 5. Communication [1] The present paper reports the synthesis and structure elucidation of the two title compounds. Treatment of the 4-phenyl-1,2,4-triazolin-3,5-dione adducts of vitamin D₃ with BF₃O (C₂H₅)₂ and KOH/butanol yields these two new vitamin D₃ double bond isomers.