Diastereoselective formation of chiral 2, 2′-spirobibenz[d]chromene derivatives. Evidence from circular dichroism and crystallographic data
✍ Scribed by Jacek Gawronski; Krystyna Gawronska; Andrzej Katrusiak*
- Book ID
- 104204635
- Publisher
- Elsevier Science
- Year
- 1989
- Tongue
- French
- Weight
- 614 KB
- Volume
- 45
- Category
- Article
- ISSN
- 0040-4020
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✦ Synopsis
Condensation of optically active ketones, (3R)-methylcyclohexanone and 5~ cholestan-3-one. with 2-hydroxy-1-naphthaldehxde* brings about formation of chiral 2,2'-spirobiben~d]chromene derivatives with diktertoselectivity 75% and lOO%, respectively. Absolute configuration of the newly formed chiral center was determined through the application of the exciton chirality method and for the 2,2'-spimbibenz[d]chromene derivative of (3R)-3-methylcyclohexanone con&med by the X-ray crystallographic study. Illtroduct ion Condensation of 2-hydroxy-1-naphtaldehyde with a,a'-unsubstituted ketones Zn the acid solution, -followed by treatment irIth the base, beiitge about formation of 2,2'-spirob'ibenz[d]chrom&e derivatives 1 which have C2-syraaetry / \ & 00 00 la,b la-3a f$,~e,R~=R~=ti Scheme 1 Chiral2,2'-spirobibenz[d]chromene derivatives Circular diehroisa examination of the spiropyrans le and lb of weaker Cotton effects in the range 330-280 nts atld strong typ*wkl-fosp &tSrai-i&ratseke*-?aP %IZi+c%B iat%Eaetisn-sf phores, at shorter ravelengthss*10 (Table ).