The synthesis of some chromans via o-quinone-methide intermediates

Buyukkidan B., Bilgic S., Bilgic O.

SYNTHETIC COMMUNICATIONS, vol.31, no.8, pp.1263-1270, 2001 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 31 Issue: 8
  • Publication Date: 2001
  • Doi Number: 10.1081/scc-100104015
  • Journal Name: SYNTHETIC COMMUNICATIONS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.1263-1270
  • Eskisehir Osmangazi University Affiliated: No

Abstract

The inverse-electron demanded Diels-Alder reaction of 2-N,N-dimethylaminomethyl-3,4-dimethyl-phenol (5) with styrene and substituted styrenes was investigated. With styrene 2-phenyl-6,7-dimethylchroman (7,R=H) was obtained in 58% yield. With 2-, 3- and 4-methylstyrenes, 2-(2'-,3'- and 4'-methylphenyl)-6,7-dimethyl-chromans (7,R= 2-, 3- and 4-CH3) were obtained in 21.7, 25, and 38% yields, respectively. With 2-,3- and 4-chlorostyrenes, 2-(2'-,3'-and 4'-chlorophenyl)-6,7-dimethyl-chromans (7, R=2-, 3, and 4-Cl) were obtained in 16, 20, and 28.5% yields. respectively. With 4-bromostyrene, 2-(4'-bromophenyl)-6,7-dimethylchroman (7,R=4-Br was obtained in 35% yield. In all pyrolysis no quinone-methide dimer (8) was encountered.