Conformational Analysis of the 10- and 13-Hydroxy Derivatives of Cembrene

Article abstract of DOI:10.1021/jo00106a015

Conformational analysis of 10- and 13-hydroxycembrenes 4, 5, 7, and 8 has been carried out using NMR methods and molecular mechanics calculations.The results indicate that the conformational states of all investigated compounds in solution are characterized by the same orientation of double bonds with respect to the average plane of the macrocycle.Alcohols 4 and 8 are conformationally homogeneous, and their solution conformations correspond to the known solution (and crystal) conformation of cembrene (1).In the case of alcohols 5 and 7, there is additional conformational flexibility in the C(8)-C(11) molecular fragment.The influence of simple substituent (hydroxy group) effects and an intramlecular OH^* ?-hydrogen bond on conformational states of the cembranoids are discussed.