7-Alkyl-7-hydroxymethyl-3,4-dimethoxynorcaradienes: A new type of norcaradiene stabilized by π-donors

Article abstract of DOI:10.1016/0040-4039(95)01882-I

Introduction of an alkyl (aralkyl) substituent at the 7-position of 7-ethoxycarbonyl-3,4-dimethoxynorcaradiene (7a) gives fairly stable norcaradienes (NCD) (7b-f). The reduction products (8b-f) of NCD (7b-f) exist mainly as NCD form especially at low temperature, although 8b-f no longer possess any π-acceptor at the 7-position. The present results clarify that two methoxyl groups as the π donors at the 3,4-position stabilize the NCD structure.