RCM for the construction of novel steroid-like polycyclic systems. 1. Studies on the synthesis of a PreD3-D3 transition state analogue.
Natural and nonnatural polycyclic systems containing eight-membered carbocycles constitute a large class of compounds of importance in organic chemistry, biology, and medicine. Here we describe a new strategy by which complex polycyclic steroid-like systems can be constructed on the steroid CD framework, by a combination of RCM and Heck cyclizations. The method is exemplified by its application to the stereoselective synthesis of 6-8-6 fused carbocyclic systems that mimic the putative transition structure of the isomerization of previtamin D3 to vitamin D3.
García-Fandiño
Rebeca
R
Departamento de Química Orgánica e Unidade Asociada ó C.S.I.C., Facultade de Química, Universidade de Santiago, 15782 Santiago de Compostela, Spain.
Aldegunde
María José
MJ
Codesido
Eva M
EM
Castedo
Luis
L
Granja
Juan R
JR
D002762:Cholecalciferol / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000737:chemistry; D003500:Cyclization; D015394:Molecular Structure; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry*; D013237:Stereoisomerism; D013256:Steroids / Q000737:chemistry*
D011084:Polycyclic Aromatic Hydrocarbons; D013256:Steroids; D002762:Cholecalciferol; C025168:previtamin D(3)