Synthesis and Photochromic Properties of Cycloalkylidene Fulgides
作者:Teck-Peng Loh、Wei-Woon Wayne Lee、Leong-Ming Gan
DOI:10.1055/s-2005-917082
日期:——
A series of cycloalkylidene fulgides have been synthesized using β,γ-unsaturated diesters, instead of the usual α,β-unsaturated diesters. A study of their photochromic properties revealed that an increase in the cycloalkylidene ring size caused a subsequent decrease in the formation of the closed form from the open form.
A stereoselective synthesis of decahydrofuro [3,2-d]-isochromene derivatives has been achieved by the condensation of cyclohexenylbutane-1,4-diol with aldehydes in the presence of a stochiometric amount of BF3 center dot OEt2 in dichloromethane at -78 degrees C. Similarly, the condensation of 2-cyclopentenylbutan-1,4-diol with aldehydes provides the corresponding octahydro-2H-cyclopenta[c]furo-[2,3-d]pyran derivatives in good yields with high diastereoseleetivity. It is an,elegant strategy for the quick construction of tricyclic architectures with four contiguous stereogenic centers in a single step. These tricyclic frameworks are the integral part of numerous natural products.