Highly Diastereoselective Photochromic Cyclization of an Indolylfulgide Derivative Possessing <i>C</i>2-Symmetric Chiral Diol as an Auxiliary

Abstract

Abstract An indolylfulgide derivative possessing an orthoester-type functional group on the acid anhydride moiety with a C2-symmetric (S,S)-1,2-bis(1-hydroxypropyl)benzene was prepared. Irradiation of 313-nm light produced the colored form in 90% diastereomer excess. The [α]D values for the colorless and the colored forms in toluene were +82° and −420°, respectively.